How many stocks and ETFs should I have in a portfolio?

Would appreciate any expert insight. How many bundle of stocks and ETFs is too much? What would be the ideal amount?

I have a time horizon of about 20-25 years. Right now, I’d like to buy 35 stocks and 15 ETFs for my portfolio that have historically beaten the 5-year and 10-year returns of the S&P500. 25 mega/large and 10 mid/small. For the ETFs, they would consist of the S&P500, Gold, Growth, Tech and a few others that have had the highest returns of the past 5 and 10 years, avoiding as much overlap as possible.

Is that too diversified of a portfolio where I won’t realize quality returns (ie, enough to beat the S&P500)? What would you recommend?