During the summer months yeah, but I've been there last year during the end season and, although there are still lots of tourists, it's not overwhelming and some of the hikes were pretty chill.
Going straight to the Torres themselves will usually be crowded (depending on the time of the day). But some of the other hikes less so. I've done the W Circuit (a multi-day trek) and during some days I barely saw another hiker.
I hate visiting touristy cities but I mind don't mind it as much in nature areas. Mainly because the nature isn't changing itself for the tourists.
I visited Torres de Paine and it was refreshingly different from national parks in the US. On the upside, you can get water and basic snacks at the refugios which reduce the load you have to carry, and makes for an overall safer experience than unsupported wilderness backpacking but still with minimal impact on nature. On the other hand I did not like that they close a lot of viewpoints long before sunset.
"Nevertheless, recent paleoenvironmental studies performed within the Park indicate that fires have been frequent phenomena at least during the last 12,800 years."
So fires are a normal thing there, or they have tourists since 12,800 years ..
Yeah I hate that, but at first glance it didn't seem to be a huge problem in TdP compared to most other national parks around the world I have been to. Most people I encountered seemed quite responsible. Chile is overall a very well-educated country though, and TdP takes significant effort to get to compared to so it is perhaps a natural filter.
Going straight to the Torres themselves will usually be crowded (depending on the time of the day). But some of the other hikes less so. I've done the W Circuit (a multi-day trek) and during some days I barely saw another hiker.