Thermal Camera - are the cheap ones really that bad?

I want to get my hands on a thermal camera for some insulation improvements in my home and can't find much good info online. I am completely new to this so maybe I just don't know what to look for.

Local libraries by me do not have them in stock. Home Depo wants $90 for a one day rental for one. Good ones are in the thousands of dollar range. So looking at low range ones, I do see some on Amazon for as little as $150. The resolution is not as good as the expensive ones of course, but it does not seem that much worse.

FLIR makes one that connects to your phone for $200 which seems reasonable but it has 80x60 pixel resolution which seems pretty bad. It also has worse accuracy spec than This $140 one on Amazon ($60 coupon is available)

This is normally something that I would turn to Project Farm on youtube for but they don't have videos on thermal cameras. Looking at reviews of these cheap thermal cameras on youtube, the reviewers do seem to say that these cameras are even better than FLIR cameras for 2-3x the price. But I have no clue if they are being paid to say good things about them.

What am I missing?