Yes, the drive and YouTube upload speeds were capped for mobile but I tested it on the Chaiwala's airtel 200 Mbps plan I got similar results. So I verified it was capped by
Google.
And about
Google play store speed fluctuations as you've also shared your play store speeds I can confirm that it's also due to Google's capping or poor ISP QOS. Even my Chaiwala's
Airtel Xstream was behaving like 18-23 MB/s on play store (fluctuating).
And yes
@Lolita_Magnum I can totally agree with you for the problems you're facing. I know their technical team is just...

You already know as you've got to meet and talk to them. But overall I feel it's good. As I never had any major issues with it except fiber cuts. Which I already mentioned. Man my English is getting really really poor since 12th. Mimicking that RIP English stuff actually affected my grammar & all. Earlier grammarly used to correct a lot less but now it's a lot. Anyways... But I'm planning to do a lot of stuff by end of this year when I'll get hands on my new gaming
laptop. Right now I can't play big games which requires public IP etc. Maybe then I'll start cursing Excitel & would need a lot of help from you & other really helpful people from this forum. Right now my only thing is uploading YT videos and streaming/downloading many videos/movies/games etc and excitel is really shining there without hiccups. Right now I'm in touch with google team to see if they can help me (I probably don't think it's gonna happen as they can't & won't remove the cap just for one user

).
And yeah what's your status? Did they pick up the ONU?