Actually the hotter peppers tend to have much more flavour. Jalapenos are a more flavourful than similar weak peppers, making them popular. However if you’ve built just some tolerance for hotter peppers and you don’t really notice the heat, that’s where flavour town starts and there’s so much variety.

I make a lot of sauces and chutneys, and habanero is my favourite for its super strong flavour and versatility, despite not being too hot. But I also love some of the stronger peppers (like ghosts and reapers) for their heat. Like reaper has an acidic burn that goes amazing with vinegary sauces, but also has a fairly good flavour.

Different chili varieties definitely have their own flavors. Even blindfolded you’d probably be able to tell apart sauces made with poblanos vs banana peppers (both can have basically zero heat).