When I was younger, I did more individual stocks and many different funds/etfs. Felt great when one did well, and I still hold some that have 10x gains. Some of those 10x gains were a decade ago, and have been pretty flat since then, but they’re still 10-baggers. I, too, tended not to put more into those big gainers, partly because they now seem expensive, partly because investing more would reduce my total percentage gains. When I was young and your portfolio was small, those individual wins had a big impact on the portfolio and it felt important to get the best possible immediate performance.
Over the years, though, the differences between funds average out. Gains over a year or two become a small fraction of the gains over a decade. I can see that some of my winners are only winners because I happened to buy them during a recession, like anything bought during the Covid panic. It’s become easier to dismiss the effect of stock/fund picking, and I’ve consolidated most of those funds into the stereotypical broad market indexes. Focussed ETFs, like LIT or QCLN, are safe from incompetence or fraud in individual company leadership, but the next administration can kill whole sectors with a change in tax or regulatory policy.