Practical tow capacities not the extremes or limits?

Seems like a bit overkill considering I tow a 7700# GVWR trailer with an F150 Lariat. If there are future plans to upgrade to a 5th wheel, then I can see it, but just seems to be more truck than actually needed. Will it also be a daily driver or a garage queen when not towing? Take into account the non towing uses of it as well.

Those old iron pushrod engines are good motors, outdated, but good, reliable. Don't think you should have to worry about the engine. What about the transmission?