The rebate level was a government set "incentive" to motivate people to go solar.
This has been reduced several times, getting it to a level that represents to the energy company the wholesale cost.
I looked at solar a year or so ago, and a 5KW system was $12,000.00. Same company, now that the grants and incentives have decreased, are selling systems for under $7,000.00.
Those that got in earlier paid a premium for the system, but provided they stay at that house they'll do OK being locked into the earlier rates. People buying now are getting the benefit of the decreased price of the systems that seems to have followed down in pricing as the tariff dropped.