It's hard to tell. Rules without actual gameplay is like selecting a new car without a test drive.I do agree with you that a number of 5e products - especially some of the adventures - have been underwhelming. That being said - just because the adventures/settings aren't to your taste, doesn't mean the rules are the issue. You can use 3rd party products or make your own adventures with the 5e rules.
... unless you don't like them either, of course.
I've seen constant failure with the 5e rules because the adventures are (IMO) bad.
When I try to run 5e even with my own content, it still fails because (again, IMO): the monster design is way underpowered (or the characters are overpowered), the encounter math doesn't work, there's nothing to spend money on, bonus actions are confusing and bad design, and there's not enough tactical interest.
Maybe others (MCDM, EN Publishing) have figured out ways around some of these issues. WotC has certainly shown no steps to addressing what I think are the shortcomings of the system for the past decade - and judging from the playtests, it's unlikely it will be improved for the next decade.