The only way is using those adapters.
I suppose the problem would be whether the result would be fuzzy or pixilated. I’ve never used such an adapter, so I don;t know the answer.
The cheap adapters will simply output 480i signal. (does anything put out 480i any more?) The fancier ones will upscale that to 720p or 1080p, which is what a DVD player is usually doing when the content is DVD not Blu-Ray. To avoid obvious pixilation (squares) a good device will interpolate the values between two pixels. The next question is how sharp is the output from the videogame device? In the days of fuzzy 480i TV I don;t assume sharp output was a priority, whereas older coputers, if they output 80 characters of text horizontally, still needed to have sharp output.
I see there are a number of cheap devices that capture RCA-jack analog video to USB so it may be simpler to route the video through your PC if it has HDMI output. These seem to get about a 3 out of 5 rating on Amazon. Read the reviews.
There’s a fair amount of discussion in graphic design circles about how the best retro game makers knew the limitations of the old CRTs and deliberately planned their images to exploit the blurry blobby pixels.
Some sample comparisons lifted from various pages and threads:
The thinking goes, these designers took advantage of the imprecision and smearing to create soft edges and color gradations, which now don’t read correctly on modern hyper-crisp monitors.
So while the image quality might be better in absolute terms on the newer screen, your perception of it might be worse.
I have a Smart TV from Insignia that is just a few years old-- bought it just before lockdown, although that was a coincidence-- and has a coaxial receptacle; it therefore will connect directly to my old NES.
It automatically displays at the correct aspect ratio, and looks great.
It’s not 52 inches-- I’m thinking it’s 36", although I didn’t go measure it-- but I remember it was some oddball size, and was on sale-- maybe it’s 40". Anyway, it’s bigger than 32", I’m sure of that.
I’m surprised that if my NES, which is the old style, and was bought the first year they were on the market, has a coaxial connector, later systems don’t. Also surprised that all TVs don’t have coaxial connectors, because I’m pretty sure there are still places where you need them.
Actually, the cheapest ‘adapter’ is a simple RF modulator. Assuming your TV has a coaxial cable TV input, you hook up your game to the modulator, screw the modulator cable into the cable input, tune your tv to the correct channel, and off you go.
That’s actually how it was done back in the day. Very few TVs had even RCA jacks, let alone S-Video.
$25 Canadian at Amazon, so probably $15-$20 in the US. The quality is not as good as direct video input, but it’s cheap and easy and you can see if you want to play the games withiut investing a lot.
I got an HDMI adapter thingy for my N64. It fits where the composite output plug originally installed, seamless. Da picture looks fine to me but my very casual playing might not notice problems. It was about $25 on Amazon.
My concern for any too fancy upscaling adapter would be added lag to the game play, which would make the experience worse than just blocky graphics. The simpler the adapter the better.
In fact, I wouldn’t be surprised if the OP already has an RF adapter for the Genesis, at least. If the OP actually owned it back in the day, it probably would have come with it. It would be specifically for the Genesis, and not require any external power.
By the PS2 era, these no longer came in the box, as TVs were more likely to have the connectors. But they still were an option. However, a lot of people did actually use RF modulators. However, these, unlike the bespoke ones, tended to require external power.