Definitely not seeing Alphabet's 20:1 split in July 2022 when I glance at Yahoo Finance charts - you sure about that? Or are you saying they're adjusted for some corporate actions but not for others?

EDIT: OK, I see there's a note that close is split-adjusted but not dividend-adjusted.

I use TradingView for most of my charting and at the bottom right side there's a button labeled "adj". Clicking it will toggle whether the chart you're viewing is dividend adjusted or not. Very convenient for quick off the cuff comparisons of returns.

Using SPY I can easily see the non adjusted returns from the bottom of the GFC to the top in 2021/2022 were a little over 600% but then accounting for dividends see it's actually a bit over 800%.