That is the computing business. There is no actual accountability, just ass covering
See the sales team from Google flew out an executive to NBA Finals, Azure Sales team flew out another executive to NFL superBowl and the AWS team flew out yet another executive to Wimbledon finals. And thats how you end up with multi-cloud strategy.
I could care less about having more vendor dinners when I know I am promising a falsehood that is extremely expensive and likely going to cost me my job or my credibility at some point.
Common Cause Failures and false redundancy are just all over the place.
Sure you can abstract everything away, but you can also just not use vendor-flavored services. The more bespoke stuff you use the more lock in risk.
But if you are in a "cloud forward" AWS mandated org, a holder of AWS certifications, alphabet soup expert... thats not a problem you are trying to solve. Arguably the lock in becomes a feature.
1) If you try to optimize in the beginning, you tend to fall into the over-optimization/engineering camp;
2) If you just let things go organically, you tend to fall into the big messy camp;
So the ideal way is to examine from time and time and re-architecture once the need arises. But few companies can afford that, unfortunately.