Linux

I like Flatpaks. They integrate fairly well, they can be used on a variety of different distros, you can install them without root permissions, and they'll often "just work", even when the same apps installed through your system's normal repos have issues.

However, if they have one significant drawback, it's that they're a pig on resources. They use a lot of storage, and when you're on a resource-constrained system, they'll use more RAM and generally run slower than apps installed from the normal repos. (inb4 anyone says "unused RAM is wasted RAM.")