Dilution is a red herring. It doesn't change the value of your shares (theoretically). What will matter is how the company spends the funds that it raises, and whether it does so in a way that generates a positive or negative return on investment.
Here's how I'm thinking about it with example numbers: I own 0.1% of the company. Based on our market and performance and valuation of peers I expect us to be worth $10b.
With no dilution my stock is worth $10mm (minus taxes, strike price, etc.)
With 10% dilution per round and 4 more funding rounds, it's now worth $6.5mm.
You expect the company to be worth $10b at some point in the future, but the question to be answered is how much you think the company is worth today. Let's say you think the company is worth $10m now, which makes your stock worth $10k. Suppose the company then raises $90m in funding and gives the investors a 90% stake. Now your shares are only 0.01% of the company, and you think "Oh no, I got screwed by dilution!" But the company is now worth $100m, because it has its previous $10m worth of assets plus $90m in cash. So your 0.01% is still worth $10k.
What matters now is how the company spends the money. Hopefully they spend it smartly and the value of the company increases 10x. Now your stock is worth $100k. You didn't get screwed by dilution, you got a $90k bonanza because the company was successful.
