You should look into MacBook thermals. The fact that fans are not running does not mean hardware is not getting too hot for comfort or longevity. Fans kicking up only when temps go over 90C (IIRC in some Linus video) is very very not good for long term use.
On MBPs, the fans “idle” at about 2,000rpm, they are just designed to be quiet at that speed, but are definitely running. 90°C is fairly close to the thermal limit of the MBP (as in, system will auto power off), so no, that’s definitely not the temp the fans turn on, but might be when they go to max RPM.