I don't think 500 Mbps for 999 or 100 Mbps for 300 is possible for airtel(at scale). Their technicians are already underpaid and service quality is already pathetic. Cutting costs even further would result in even more poor connection quality. ISPs like Excitel and Hathway can definitely provide 500 Mbps for 799 or 899.
Anyone who
really needs a 500 Mbps connection would be capable of paying 2000-3000 a month for that kind of service.
I am not defending Airtel at all. They discontinued their vfm black plans last year which was pretty annoying for me. Maybe it was their strategy afterall to increase prices/remove certain plans once decent expansion is achieved.
There are two sides to the argument:
1. Only a small portion of broadband enthusiasts like us care about the raw speeds. For the masses, they just want a bundled OTT + internet bandwidth plan to cater their entertainment needs not caring about the upload and download speeds. Basically broadband being replaced by cable
TV. It's a good move in a way where households have access to fast internet connection.
2. Maybe folks at Airtel noticed some data on the excel sheet and decided to discard the 200 Mbps plan and bundle it with popular OTT apps with a lower speed. Again not defending Airtel but 100 Mbps of connection is all you need in a regular household who streams content on the internet. They should have ideally not removed the 200 Mbps plan and still kept it as an option but maybe they had some aggressive deal with the OTTs so they decided to go nuts with the plan bifurcation(just pure guess). This decision is most likely proposed by some MBA guy from a bigshot college

. Maybe they thought "nobody is buying the 300 Mbps plan so let's cut the 200 Mbps plan and force people to pay more for our shitty service

.
The only option would be to switch ISPs if one really needs raw speeds at a vfm proposition.