I understand where you are coming from. But we have to differentiate between costs here.
The network has operating costs and R&D costs. You pay for operating costs via stake pool fees and for R&D via treasury.
I would not even write off treasury transfers as costs as all that money is basically your equity in Cardano earmarked for its future improvements. Now assuming that projects that get financed by treasury create value for the network, you actually earn “dividends” on treasury transfers through increased adoption or higher market value of ADA.
Let’s say you are entitled to 100 ADA through staking. Of this amount you are likely to transfer 20ADA to treasury and pay say 10ADA to a stake pool.
Here your real costs is just 10ADA, which you can choose to avoid if you solo stake.
The point I make is that you don’t necessarily get diluted by 5% lets say. But by 0.5% if you delegate.
You may keep all of your 5% reward but pay electricity cost for staking on your own. Assuming you have a 200w computer that runs 365 days and electricity cost of $0.08 per kWh, that works out to just about $140/year.