AWS has established itself as being highly backwards compatible - and the cost of that seems to be the long-winded process you described. If they were more liberal with what features they implement then they would have to either be more liberal with what features they deprecate (removing a core value proposition of AWS: backwards compatibility) or they would have to suck it up and deal with the bloat which would naturally lead to higher cost and overall slower delivery of new services.

For a counter example see GCP. One of the biggest barriers to entry is trust: no one wants to use it because they don't trust Google to not arbitrarily yeet features out the window with six months notice. Whether or not that's actually what GCP does, it's how people perceive Google.

I'll take AWS's approach for things that I work on professionally and have to support for many years.