It may be but no one is doing it because the airlines are checking. I was in India recently and I speak from personal experience. There is absolutely no reason to do it because you can get it within a day and it's inexpensive.. costlier to fake. There are more fakes from western countries than India which has a centralized way of verifying authenticity via qr code.
Well it was much earlier in the pandemic and the govt set up a validation site in response to this.. so your information is old. I was there last month and the pct test is ten usd and they have to send the results to a govt of India site and the result must have a qr code that the airlines look at to confirm its validity.
No fake certs from India.. they have a qr code that links back to the govt of India website. PCR tests are just $10 in India. Stop with your incorrect slander.
Also in larger hotels they submit them electronically in a batch so you can't get a copy from them. This happened to me at Hua Hin Marriott. However the immigration office didn't ask me for it. In fact at Hua Hin you don't need to fill any forms except the address form for a 30 day extension. They will make the requisite copies themselves. Amazing service.
Best is to buy the pcr test from Amazon and they will send the results on time most of the time. It's one of the least expensive options. It will work for the 72 hour requirement.
Such a scam when in India they will come to your home and take a swab for a PCR test for 15 bucks. Or you go to the lab for ten bucks. These places in the US and especially Thailand are making so much money off these tests.