Regarding Rajputs I don’t think they’re useless it’s just I can never afford them. Gaving something between a rodelero and a pikemen is/was useful but never critical.
They cost wood and between villagers houses and mahouts, you’re spending it all anyway and you need to put more villagers to coin for more useful stuff.
they’re never good enough to put extra effort in.
For me it is fine to nerf sepoys if we buff rajput properly. I feel the PUP update is not a significant buff, as it barely increase their dps.
I would compare rajputs with halberdiers, as they cost roughly the same in vil/s and have roughly the same dps against cavalry:
So actually rajputs are good in supremacy age 2, especially when using wood crates. But as soon as you are in age 3, you really wish you had a standard halberdier.
I think is not that India players forgot that there is something else than sepoy+gurkha+siege ele, but more that they wished there were something else.
Even though I feel the nerfs (sepoy+karni) will hit the civ very hard, I am not that concerned yet because India seems to have a big player base, despite not being nearly as healthy as Britain and China.
Well that base will shrink fast as the use of mercenaries increase and india will haveNOTHING against mercenaries 
What should an Indian player do with a Lanskanet spam ? dopelsoldner spam ? maigidi spam ? Maceman spam ? french Halb spam ? Oromo spam ? and any other merc spam ?
Well said.
Consider adding the new consulate card for cheaper armies into your deck. I would kill to have that for all Asian civs.
Stop him before he does and if you fail use all you have is the spies from the consulate to farm him or else defeat. Other solution go to 4 age and use urumi. I think they should have an anti mercenary mercenary or anti mercenary unit like the Japanese with ninjas (which they don’t need because their units are ops). I don’t think they would be able to spam huge mercs I think they can still keep mercs although difficult when they have too many
Overall musketeers without bayonets (or spears) having less cav multiplier seems like a good change to me. Sepoy used to be the only exception.
Balance wise they could make other counter cav units more viable.
They aren’t done for they are still very good in ranged combat. They are marginally worse in melee. Sepoys were just completely overshadowing everything india had (india has like 4 units that deal bonus damage to cav). And mass sepoys were simply OP in supremacy, good damage in melee and range and trivial to mass.
Doesn’t india have arguably the best light cav with the best shipments for said light cav in the Howdah? Pretty sure most other civs cant fight off an Ottoman FF sipahi/Mam push with one shipment. Really, this kinda justifies the rework - so much focus on the sepoy as an all pupose unit peeps forget about the specialists.
Coz the zamburaqs are absolutely useless, rajputs will perform better against elmetti, no other use case to use them, and the howdah is a great anti-cav but it cant hold the lines, and still have its limitation, none of these can become the goto unit of India.
So the obvious cost and pop effective choice was sepoy, it was not overperforming it was jack of all, master of one. but now its master of none.
yeah, totally agree, they should compesate that nerf bufffing their other anticav units. As u said, they are kinda bad.
Zams need a buff, true. The only reason why Ruyters are usable is that they survive long enough to deal at least some damage while Zams just disintegrate on any enemy contact of any unit type.
If only India had a durable ranged counter to cav.
The sepoy age 4 card now also improves attack and hp by 10% and they recieve less from the imperial tech so that’s a buff to late game sepoy in supremacy getting that upgrade earlier without needing imperial.
But needing another card. Civs like India has too many must to have cards. -_-