Thats not true , and i can say that from self experience as i have all 2 of this cards !
I got the 1080TI for the last years now and yeb its still a good awesome card but with currently new games its not funny to play.
Thats why got me the 3060 12 Gb.
a 1080ti is still a beast of PC gaming till date, you only need to play graphical demanding titles in a lower resolution like 1080p, I am sure that the card can still push 40fps to 60fps easily at high graphic settings.
It is a beast for some games , but the time for this card is going to the limit where it can handle the performance that is needed for the today games in a good quality.
Thats why i use it for mining only now.