Does anyone hold SPY long term?

My uncle (65) and I were talking after his fathers funeral and he's trying to figure out why his father (who died at 95), was holding only 1 ETF, SPY. The capital gains are so insane that we're not sure how to part ways with it and move to something like VTI or VOO, IVV, etc.

We've met several "shady" people who are willing to "exchange" (as in something like 1031) the assets in return for a "fee".

In any case, while that discussion continues on, I wanted to know does anyone actually hold SPY long term (outside my uncle's father)?

The theory right now is that he invested in SPY when it was launched due to his connection with Boston Life Insurance companies or something, reinvested the dividends and the rest is history.

So this brings me to people here. Has anyone held SPY for say 10 years?