You clearly know nothing about 4e if you are asking this question. 4e has a very specific and well-thought-out improvisation rule. Beyond that it has SCs that allow you to deal with more complex situations.
Arguing about the number of options available in each edition is pretty pointless. I've played both. 5e characters generally have several options. At low levels they're probably roughly comparable, but there's no comparison between a low paragon 4e fighter with 4 daily powers, potentially 5 or 6 encounter powers, 2-3 at-wills, and most likely some variations on these things based on feat use or just reasonable optimization of charging, bull rushing, etc.
Sure you can have more options than '6 ability scores plus the imagination'. If character A has 4 things on his sheet that he can do explicitly, and B has 3, then by gosh A has more options! Beyond that you haven't listened. The improvisation rules in 5e are notorious by their virtual non-existence. Yeah, you're told 'set a DC and use Skill/Proficiency/Ability checks' but since the DCs have NO LEVEL ATTACHED there's no good guideline as to what DC to use, none at all! In 4e its quite simple, I know that I'm using a level equivalent DC that makes the moderate DC likely to succeed for a character who would normally be expected to face this hazard/task/whatever. If the situation makes the task easier then I use Easy DC, or if its harder than usual I use Hard DC. There's room for DM judgement there, but I can pull a DC for anything without any need to think hard about it.
I think 4e's system can be improved even more, but it is very much a step up from 5e's.