I don't think this has anything to do with the lockdown, but is all about how cheap bandwidth is in India now. With Jio entering the market and cutting mobile bandwidth prices by 98% or more, no Indian user has an incentive to cut back on bandwidth use anymore. As a heavy YT user, I used to cut back most of my video watching to 480p, to at least not hit the daily 1GB quota, but I just ended up getting a couple more SIM cards late last year and watch most everything in 720p ever since, racking up around 50 GBs of YT video monthly.
Once Corona hit, they wouldn't let me go over 480p on my phone, which I used more, but still allow 1080p and higher on my tablet, so there seems to be some kind of device profiling going on (not based on YT account as I never login, and if they force it, I delete the app's storage and my preferences just to get back out again). They should just sell gift cards and let us pay by the video, but since they stupidly don't do that, we get these strange limits instead.