It would make a big difference to anyone who is fighting thargoids, bounty hunting, engaging in PvP, doing BGS, explorers needs fsd boost mats, or even powerplay participants. Mats go fast. It sounds like you don't do anything of these things and have no use for mats but you are in the minority here.
Most of those activities require an upfront investment of mats to get an engineered ship, but don't then use a lot of materials for ongoing activity. I've done a lot of engineering of my ships for various purposes ... but I've now done that engineering, and don't need to do it again. I threw about 20,000 (mostly low-grade) mats into the Colonia engineers on modules I just discarded and re-did afterwards, to boost their available grades, without needing to spend more than a few hours replenishing my stockpiles afterwards.
Explorers only need FSD boosts on the distant regions of the galaxy - and sure, dropping in to do a CG once in a while might be a way to stock up, but you can get them easily while out there without having to make a massive round trip, by looking for volcanism sites.
You also think CGs are underpaid and think that paying more wouldn't help so I am not sure how you square that but I'll leave that one to you.
I think paying more would be sensible as it would bring them into line with other general earning methods (by which I mean the ones in the 5-10 million range, not the 50-100 million one) - and various other activities developed early on such as Powerplay and CQC would similarly benefit - but anyone actually wanting money would still be better doing something else, and so probably would continue to do something else. I'm suggesting multiplying payouts by 10 would be good. To bring them into line with Void Opals would require considerably more than that.
The reason is because people are not being adequately compensated for their time and effort.
It's a computer game.
The compensation you receive for your time and effort - unless you're doing something against the Terms of Service - is 0.00, plus any actual fun you had in that time.
Increasing the credit payout doesn't change how fun the activity is at all - it just means that rather than complaints about "having to grind Void Opals to make money" we'd see complaints about "having to grind CGs to make money". And then, according to you:
What I can say, is attractive pay will attract more people and more people can buy the ships they want and equip them as they want so they can go do the things they like in elite rather than grind in the hopes of doing. That is the answer to "Then what?".
...they would, having made enough money for their needs, stop doing the CGs again.
Conversely, people do Powerplay, do PvP, go exploring (not road to riches), fight Thargoids, etc. ... despite all of those things having terrible credit/material rewards. Why? Because they're fun.
I fully agree that it should be relatively easy to get the money and materials you need to do the in-game activities you actually find fun. But I think CGs should, by and large, be the activity you do once you've got the money you need because they're fun, not the activity you do to get that money.