[iamflimflam1]

I would really question why these are your major concerns.

You are going to burn through a lot of time and resources worrying about cloud lock in and being cloud agnostic.

That’s energy that should go into building your product and finding customers.

[mekster]

You're just over generalizing it. You would burn time dealing with the way of the big 3 instead of learning what you're using and if you ever want to migrate out, you'll be burning more time than you may be able to afford.