If it crashes when launching the game:

https://github.com/ValveSoftware/Source-1-Games/issues/5043

Tl;dr; Use the Flatpak or replace libtcmalloc_minimal.so.4

cd "~/.local/share/Steam/steamapps/common/Team Fortress 2/bin/"
rm libtcmalloc_minimal.so.4
ln -s /usr/lib/libtcmalloc_minimal.so.4 ./

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If it crashes on VSH maps:

https://github.com/ValveSoftware/Source-1-Games/issues/5044

Unfortunately, there is no known fix.