So are you saying that this kind of situation is considered OK by most people's standards, so long as the party in control acts as a "benevolent dictator"?
Yes a lot of people are okay with one company controlling 80% percent of a market if - they get there by relatively fair practices, there are clear and viable alternatives, and the consumer isn't forced to use them.
Now if the behavior of the "winner" starts to have clear, negative effects on consumers and consumers are no longer happy, the story changes considerably.
Maybe I could see an argument against the greater Google ecosystem (Android, Google Play, which does lock you into Google), or the distributor of content also being a content creator, etc.
I agree about their search, but problem with Chrome isn't just lack of alternatives. Problem is that Google have too much power over web standards and all of competitors have to follow. Even Mozilla had to implement DRM.
Gmail is similar: Google never directly used their power against competitors, but they make email a lot more centralized. Their intransparent anti-spam make it much harder to run own mail servers or send notifications / newsletters, etc.
Of course almost any company with 60-80% of market share would likely do the same and this is why it's bad.
If there feature video on YouTube / Netflix won't play without everyone going to implement it anyway.
Another way to improve situation is to get rid of shady black lists BS like Spamhaus and replace them with proper organizations. Google could also create some consortium to improve protocols, implement easy to use mail servers that send everything properly out-of-box, then enforce DKIM usage, etc.
But no, Google need nothing of it because they have huge market share and directly benefit when non-Gmail services become unreliable.