I recently got myself a Type 2 M1Garand which I had the joys of taking out of the grease (can't wait to shoot it more once my range opens up again). I am shocked at just how ergonomic this rifle is. Safety is easy to engage and disengage. Sights are easy to use and effective. Loading is extremely fast with the 8rd clip, and if I practice a bit I am sure I could get very efficient with it. You can also keep a really low profile which is something that isn't as appreciated these days.
I would take the 8rd clip over a 10rd detachable magazine any day. No requirement to load magazines before hand, your ammo is issued on clips already. If you run out of clips your literally out of ammo so that isn't a issue. No damaged magazines to worry about. Just overall a fantastic design and until you start getting into the 20rd magazine range you really wouldn't see much of a rate of fire difference. It is also easier to produce all those clips than it is to make magazines. Plus if they were a 10rd magazine I guarantee you the military would have been insistent on stripper clip loading like just about every military at the same time period, which is slower than shoving a 8rd enbloc in.