The problem with under23's at our level is that by the time a player gets to 20/21, if they haven't made it into the first team then its unlikely they ever will. So the under23's team is essentially an under18's team with maybe 3 or 4 max 19 year olds in it.
Far better that these lads are loaned out to non league teams and they get to play 'proper football'. Bridging the gap between under18's to under23's is very costly, the higher up you go in the leagues the more benefit having one (23's team) is though obviously.
You mention Exeter - just googled them - not sure if its accurate but if it is then they don't exactly play many fixtures!
https://uk.soccerway.com/teams/england/exeter-city-u23/40148/Essentially, there is a gap at our level (generally) where a player that gets to 19 and isn't quite good enough for first team, hasn't anywhere to go within the youth structure. So he basically has to go out on loan. This season those feeder leagues all stopped early after hardly playing, and that has been the case now for 15 months so its become a real problem, very much caused by Covid. Will be more like 18 months when the season re-starts, thats almost a generation of young pro's that are struggling to progress for no fault of their own.
You may get a business/s to sponsor it, but that would only be money they'd have spent sponsoring something else at the club. So no extra revenue would be generated, as such. Just a cost base added for very little potential benefit.
I've seen reports that Sunderland are looking at a couple of our young lads, but Sunderland (league1 they may well be) are a totally different level to us financially so its non comparable. They were in the prem not too long ago.
I don't think the issue is with our academy as such, more a case that short termism is always a key element to decision making by whoever the manager is. Chuck didn't even start yesterday, no idea why not, but unless these prospects are given a run in the first team then they will never 'make it' with us. Its almost like we need to have a policy where the manager has to pick 2 academy lads in the starting line up! Because they will always go for the tried and tested players, even if they are not performing well.
A classic example is Ivan Toney. Wilder stuck by Sinclair right until half time against Pompey, 2.5 games before the season ended. He'd been useless for weeks yet kept getting picked. Toney was finally given his chance, the rest as they say is history. If Sinclair had tapped in a goal that half v Pompey, he would have no doubt played at Dagenham and we'd most likely of gone down!!
Why's Bolger been on the bench in recent weeks, when Max Dyche hasn't?
Im not critising Brady by the way, either. I just 'don't really get it'. We have ALWAYS favoured old expensive donkeys over our own prospects whoever has been the manager. Im not saying we should take risks or play kids for the sake of it, but when you've got subs that are never going to come onto the pitch unless we get an injury/sending off, then I see no point why they are even on the bench. Those sub spots would surely be better taken by young prospects?
Sorry for the long post, Ill get back to my day job now!

Agree with the first bit but it is crucial to give these young players time to develop. Like in any sport, different players will develop at different rates. I still think an U23's is serving its purpose if we know by the age of 21, whether or not, a player is going to make it or not. If you are going to send young players on loan, the club needs to have some input in this, rather than leave it to the first team manager. I trust JB to do the right thing but that can't be said for all managers. I agree about Toney. Was at the game when Sinclair ducked out of scoring into an empty net. To be fair to Wilder, to a point, a lot of other managers still wouldn't have bought Toney on in the 2nd half of that game.