My opinion.
It's not needed, but it makes life easier.
You can hit rocks, roots and ride differently with some front sus. I like it be they MAGs' bombers or JUDY. For grass riding and bridleways at country speeds then your tires will be doing most the work.
Front sus works out the saddle, so ignore the chap up there
It all depends what you want out of it. You'll most likely be able to ride a bit longer or not feel so battered.
Take a ride I did with a mate for a reccy. Part of it he had to get off and walk on his rigid forks, I rode as I wasn't getting my arms battered so much on the horse/cow churned up path.
Keep your eye out and do it. Really smooth JUDY's are nice, the slightly warn ones not so nice. Often pot luck though.
Bombers are often more reliable in being in smooth working condition though a bit heavier.
You can always switch back.
OR pop along the the Peaks National ride and realise that 80 and 90's bikes of all type can be ridden and arm wrenching chalk paths
