There is too much misinformation in the Linux community, to the point where even Linux veterans are even misinformed. That said, I've created a list of a few common misconceptions and their truths, all typed below. This also isn't like some of the Linux myth lists online that just include worthless garbage like "Linux can not play DVDs or any other media", "Linux can't play music", or my personal favorite "Linux can't open images" (all real examples from a list of "common Linux myths").
1/4?
Myth 1; Linux is more secure because FOSS!
This is false. Linux is actually notably less secure, due to lacking exploit mitigations, no sandboxing, etc. While it can slightly improve it, no amount of hardening can fix it. Linux is actually beat out in security by almost every other major OS, Windows 10, MacOS, and ChromeOS most notably.
2/4?
@ThreeBadgersInATrenchcoat I'm sorry but this makes little sense. This is no objectively true of false "fact" but very much a matter of preference and need. Depending on what you want to do and what you prefer your "best" OS may vary. Sure Linux has issues but for quite a few people it is the best OS because only it offers what they need/want.