I understand that I'm not in the European league, where probably the issues are more pronounced, but I make a largely homegrown team, occasionally I make a transfer, usually of a youth, sometimes of a senior player to fill any glaring holes or get me over the line if I am close to challenging but a little bit short.
I've never been a huge fan of sitting on the transfer market in any of these types of games, abut am aware it is the usual way that teams dominate and build their strategy around.
I get the bonus of not wasting time on the TM and the great satisfaction of winning against a team who does
Yep there are ups and downs with the randomness. It all depends how you get your enjoyment from the game. The most important thing is a full division of actives and a good match engine imo, and I enjoy watching the games mostly....apart from when ofc I get cheated by the ME

I think the supply of players is ok, the TM is a barren wasteland most of the time. To change that I think you'd need to make dominant teams have to sell youths to fund wages so that being at the top for too long is very hard to sustain even with getting all the best players from the TM.
A quick look through the top 10 teams in the world rankings, show there are 4 from the 10 who have minimal TM action. Myself and Calgary from Americas, Woody & KryptoKnights from EurAfrica - I think that's more than reasonable results for the game as a whole....forgive me if I didn't look too deeply at the other teams, most of my time is tweaking my own team and that is what I love about a strategy game, not TM sitting.