Yeah, Tal's sacrifices being unsound is more or less a meme and fails take into account the historical context the games were played in. Tal did miss some things in his calculation, but they were usually things the opponent would never find. Because at that time, essentially no one could outcalculate or even match him in complex positions except maybe Viktor Korchnoi(who somehow had a clear positive score against him) and Fischer in his prime(though since he stopped playing in his prime he never managed to get a + score). So if Tal missed a refutation to one of his sacrifices, almost certainly the opponent missed it too. It was usually some bizarre computer line. Sometimes even grandmasters analysing the games at the time didn't find them, so clearly finding them at the board was pretty much impossible.

I never really studied the Karpov-Tal complex of games but somehow all their 23 games but one were a draw, with one win for Karpov. I think this is more a case of Karpov's ability to avoid tactical complications and outplay his opponents positionally than matching his calculation. But interestingly, Tal positional play mostly survived the Karpov test, which is impressive. Tal was also much older than Karpov. His peak ELO was 1705 in 1980 which is nuts considering he was 44 by then and his health was deteriorating, yet he was still behind Karpov in his prime by only 20 ELO points. Probably all those draws with Karpov helped a lot...

In the historical chess ratings linked in GP, Tal's peak rating is 2799 in the 60s. Kasparov peaks close to 2900 in this system though and so does Fischer. Unfortunately, it seems the ratings stopped being updated ariund the mid 00s, so current top players don't have meaningful ratings :( I would love to know if Carlsen et al would come out close to the same as Kasparov and Fischer, or whether they'd still be ahead by a significant amount. Hell, maybe they'd be behind, since they don't necessarily dominate in the same way.