I think they’re both pretty common. Sometimes the work culture is terrible company-wide (a number of places I’ve worked have just felt incredibly disorganized), sometimes it’s just because of your manager (or team). If I was confident it was just my manager, I might try an internal transfer or something first.

Also, loyalty to a company isn’t really rewarded in most countries now. Just look at Google, Microsoft, Amazon, etc. laying off swathes of people every few months.