A lot of factors would be in play. Is the tent erected late in the day and struck early as you continue your trip, or is it left up for the day? Are you at altitude? Summer or winter?

In many tents, the rainfly gets the brunt of the UV exposure, rather than the body of the tent. Most rainflys are now polyester, rather than nylon.

Tents I have purchased over the last decade or so have lasted for several seasons in what would be considered as relatively normal use. Any tent will wear out eventually and UV deterioration is just one factor.

Incidentally, you can replace that factory seam seal with hand sealing. It's a fairly simple process.