Lets say your table uses the encumbrance rules. Have you ever weighed out all that cash in your back pocket?
50 coins of any denomination weigh 1 lb.
A chest can hold 300 lbs of gear, or 15,000 coins. which means it will hold 150 gp if you fill it with copper, or up to 150,000 gp if you fill it with platinum. Either way, if you include the 25 lb the chest weighs, that’s 325 lbs that somebody has to deal with.
A belt pouch (1lb) can hold 300 coins (6 lbs), hopefully the weight doesn’t pull your pants down .