Back in 1974 I got my first 'proper' Guitar - a S/H 1968 Std Sunburst Tele. That Guitar was my only electric 6 string for many years. I played many gigs with it. It never occurred to me to do any upgrades as she was perfect as is. It wasn't until I got a Strat in 2010 that the Tele took kind of a back seat. I still played it - but it only got used for specific gigs as I was becoming aware of the value of it.
Move on to 2019 when out of the blue I was offered (what I considered to be) a ridiculous amount for the Tele. The guy wanted a birth year guitar - and he liked the fact that mine was all original. After sleeping on it for a couple of days, the deal was done.
I spent about 25% of the proceeds on a new Strat and never looked back.
Everything in my world eventually go on the block. I have two basses and one strat I will never sell.... everything else is just rented from the world at large. Lately I sold a mint, first year Taylor T5 for way more than I paid for it, I loved the guitar, it was pretty one of a kind in a few ways, but dang, I took one great guitar and turned it into two great guitars, did not look back.