Alcohol evaporates at a lower temperature than water which is why cooking will eliminate much of it. But in chemical terms alcohol is very hydrophilic (ie it loves water) so the chemical bonds can only be completely broken with something like a centerfuge.
But to put things in perspective after a few hours of simmering the majority of the alcohol will be gone.
Should you avoid it altogether? That depends. If you're new to sobriety or very easily triggered it would be safest not to cook with alcohol. Certainly something with a lot of alcohol and short cooking times isn't a good idea. On the other hand, a splash of wine in a pasta may not be a big deal at all (very low amount of alcohol to begin with).
Since I quit drinking I have made Coq Au Vin at least twice. This involves stewing a chicken for hours in two bottles of red wine. The long cooking time boils off most of the alcohol and you don't drink the cooking sauce, and I have not been able to detect any effects from what small amount of alcohol remains.
In summary I agree it's something to consider but I don't think it's a big deal, at least to me. YMMV.