From my reading, yes true absinthe really is that bad. There is consensus that it is addictive and ultimately damages neurons in the brain.
That said, there is probably someone here who’s grandmother made her own absinthe and drank it every day for 60 years, smoked cigars, ate fat, and lived to be 95 when she died while extreme snowboarding in the Himalayas. Or not.
The question you’re asking pertains to dosage. What dosage is acceptable? Is there a safe dose?
I haven’t found any source that can answer that. Absinthe itself was never a single substance produced by one manufacturer under controlled conditions. The contents of Absinthe in the old days could have included methanol, cupric acetate, or antimony trichloride added by disreputable manufacturers.
The main ingredients, of course, are ethanol and wormwood. There are different species of wormwood. It’s possible that modern producers use a non-toxic species. I’m sure the manufacturers could provide a chemical analysis to interested consumers (but maybe not?)
I doubt that there are any scientific studies which investigated how much Thujone (one of chemicals that comes from the wormwood in the original Absinthe) is safe over a long period of occasional use in humans.
Summary: don’t know, probably never will.