In my opinion not required if you're not a rough user. I have been using s20 fe 5g with in box screen protector from past 5 months and haven't faced any issue. If you're a rough user in that case I will recommend buy a good tempered glass.
For me, the default protector started peeling off in 2 months and it made me mad, then my friend suggested me Gadgetshieldz screen protector. I'm using it for 3 months now and it sticks very well, also I got only minute scratches on it.
