How would elder scroll Arena and Daggerfall look with todays graphics and todays computers

Honestly, it would look the same, only the clarity would be better. This is because the graphics are limited to the game engine used, which is limited to ts time period.
They would need to recreate the game with modern game engines, which would really change the game, as Part of Arena is its "old school" feel and impressive mechanics for a 1994 game!

If you do want to play Arena in the highest possible quality, you would simply play it on YOUR computer, which will already improve it compared to 1994 graphics (screen quality).

Since it was developed for DOS computers, you will need an DOS emulator like DOS Box.

You can download them for FREE on the Official Elder Scrolls website which can be found at the related link below.