I think it's also worth looking at your oil-changing habits before always going full synthetic.
The biggest advantage of full synthetic is its extended service life. But a very great many here always religiously change their oil at least annually, regardless of mileage, or going no further than 5K miles between changes. Even with modern conventional oil, that's way, way, way more than adequate change frequency and does not even allow time for the issues of old (like sludging, which is relatively rare to begin with except in specific engines) to get a foothold.
I use synthetic oil in my primary daily driver, a 2004 Toyota Solara SLE, and my partner's 2017 Ford F150. The Toyota gets changes every 10K and the Ford whenever the engine oil life computer says the time has come. The RRs and my 1996 Buick Roadmaster Estate wagon all still use conventional oil, or sometimes a synthetic blend if it's what I can get and is on sale.
Most of the oil changing in our cars occurs well before the lubricating properties of any modern motor oil are anywhere near close to expiring, whether that oil is conventional (and very highly refined) or synthetic.