Gold has weight only works if they either give you something more valuable to convert cash into, or if there's nothing in the game that costs alot. (Like, how would you carry 25k+ gold over to the city hall to buy Fancy Mansion?)
Well, I suppose there could be bank transfers. But that starts to get away from feeling like a fantasy game, and more towards modernity.
:shrug:
In real life you can carry enough gold to buy a good house, you can not carry enough to buy a 10 million $ palace. Money for everyday use including serious shopping don't weight much.
Daggerfall had letter of credit, a check the bank or stores gave you.
However to gold and weight system in Daggerfall was totally broken as one septim weighted 0.1 weight unit, it was the only coin in the game and two septims could buy you an apple or other cheap stuff, this made gold extremely heavy, like if the only real world money was pennies. Elven equipment or better was had a better value/ weight relationship so at medium to high levels you soon started to use the drop gold button a lot.
Yes it added a lot to realism, real world thieves usually take your money and then drop it so they can take your tv, in real world money/ gold is very valuable, yes you have more valuable items like artefacts, jewels and expensive drugs but they are usually light.
For gold to have veight they would have to make it more valuable than everything except rare artefacts, jewels and light expensive items like powerful scrolls. Typically you would use copper, silver and gold coins. One gold coin would weight 0.1 and be worth 100 septims.
This would make you able to carry many hundred thousand septims, making the gold has weight pretty irrelevant.