Cool may still be in use but its meaning seems to have changed from “awesome” to “not a problem”.
Cool is definitely still used. I think it might actually have become, eh, uncool to use it in the early 90s or so, but it was definitely still used and it’s ubiquitous now.
Awesome has also definitely outlived the surfer popularity.
Wicked is still used - not as widely as the other two, but it wouldn’t sound out of place or ironic.
(I used to be a teacher, and also just checked with my daughter).
Relevant:
People rarely talk about 4x4 quarter-ton trucks.
But they often talk about jeeps.
I noticed the same evolution of that term. I remember the very first time I ever heard it: it was Junior High, start of the school year. Mid-to-late 70s. I walked past an area just off school grounds on my way there where the ‘bad’ kids would hang out and smoke before class. A girl asked one of the kids “how do you like school so far?” and he replied “it sucks d***.” That was pretty shocking to my innocent ears.
Then, as you say, over the years I witnessed the gradual PG-izing and mainstreaming of the term “sucks” until I swear I heard it used on a sitcom.
That’s an interesting observation. It currently means both to me, and I hear my 5- and 7-year-old use it to mean “awesome” or “very good” (“That’s so cool!!”) or “popular”, but also in the sense of “no problem” or “I understand.” I don’t know if those latter meanings were in use when I was growing up; I can’t quite remember. It doesn’t feel like they were, so it’s possible this additional meaning has gained prominence over the last couple decades.
Beavis and Butthead were certainly using “cool” during the early 90s:
I seriously have no recollection of “cool” ever being out-of-date during that time period. It’s possible, though, that I was simply uncool enough to ever have noticed. 
Now “hip” is a word that I seem to remember not really being used in my formative years in the 80s and 90s, but I feel like that one’s kind of normal again. Or maybe it’s just me.
When I was growing up in the 60s and 70s, “cool” was associated with an pose of hip, ironic detachment. Charles Schulz mocked this attitude with Snoopy’s sunglasses-wearing “Joe Cool” persona. If “cool” declined in popularity, it was probably because it was seen as dated and old-timey—redolent of beatniks, bongo drums, Maynard G. Krebs, etc.
The current use of “cool” is much broader these days, but it still encompasses some of those earlier connotations, particularly when people say they are “cool” with something (meaning that it doesn’t bother them). I’m sure there are lengthy articles in scholarly journals about the evolution of “cool,” but I am too lazy (or too cool) to go look for them.
What a nifty topic! (which goes back to 1900-ish).
But I can’t add more, so I feel like a dick. (1600-ish).
Replaced by the cringy “awesome” in that decade.
Bitchin’ and “radical” didn’t survive the late 70s/early 80s, except ironically. But “cool” was cool then and now.
I keep finding myself using the word “dig” for “like”. It’s not a habit I got into when I was younger so I’m not sure where I picked it up. It’s still rather archaic, isn’t it?
It’s funny, because I was thinking of the word “bitchin’.” Where I’m at, or at least among my peers, it had a renaissance c. 1991/1992 before just disappearing again. I didn’t realize the word went back that far.
“Dig” for “like” or “appreciate” is in my contemporary vocabulary. I’m not entirely sure when it became so. I don’t feel like I used it in the 80s or early 90s, but maybe late 90s?
That’s back when we all tied onions on our belts, which was the fashion of the time.
I once puzzled my nephew by calling his clothes “snazzy.” I tried to recover by telling him it probably translated to “rad,” but apparently that was obsolete, too.
I worked with a guy who used “the cat’s ass” to mean the best possible option. I wondered when the cat’s pajamas became the cat’s ass, and how many body parts were tried and rejected before settling on ass.
I’m 71 and still use “cool” non-ironically. It was part of our vocabulary when I was in 6th Grade (1962), and probably earlier. Seems to me it was something TV beatniks said while snapping their fingers.
“Awesome” was already all over the place by the early 80’s. I remember my grandmother so observing when Frank Messer used the word to describe Ron Davis’s coming in to strike out five consecutive A’s on May 3 of 1981 (he was ever more awesome the following day vs. the Angels, fanning eight straight. On the other hand, he would go on to surrender three “walk-off” [pardon the anachronism] home runs that season).
In 1982, after Reggie Jackson, in his return to Yankee Stadium with the Angels, homered off Ron Guidry the crowd started chanting “Steinbrenner sucks”. In the next day’s paper, Dick Young would report ‘“Steinbrenner stinks”, they almost said’.
He’d probably disclaim any such responsibility, but I felt that when Ken Jennings publicly used “sucks” in some such negative way, the word was as of then not particularly vulgar. Kind of like when Alex Trebek said “scumbags” on air.
IMO, “cool” is clearly the champion American slang expression of the 20th Century. I object somewhat to the phrase “before it was cool”, but I suppose it’s usually said with a wink, and that “before the squares thought it was cool” is the implied meaning.
We used it, back in the '60s. “I can dig it.”
It hasn’t been around long enough to be tested by time.
The meaning is not always immortal. John McWhorter, a linguistics professor, did a podcast recently where he talked about how “asshole” was commonly used decades ago but had a slightly different meaning than today.Then it was more like “just another average undistinguished guy.”