Luck of the draw due to IP address reputation. I host my email on a $5 VPS, but the IP has mapped to my VPS for like 15 years so it's fine.

I've built email servers that sent 15 million emails a day into all of the major inbox providers, so you could say I know a thing or two about it. This wasn't spam, it was legit doubple-opt in.

It depends on your use case, and ability to actually administrate it properly.

It can vary, I did it for a few years with no issues or deliverability problems

Lol no and no