For many years I coiled/flaked lines at the mast, draped them over mast winches or tucked them in between the halyard and the mast. They stayed exposed to the environment, gathering dirt and grime, falling on the deck, getting under foot.
Then I saw in an advertisement the Blue Performance bag. Looked like a bit of bling for the boat. They were on sale, so I bought one. They are a well made bit of kit. There are internal Velcro loops to hold the coiled/flaked lines. Now when I raise or lower the sails I remove the proper halyards, drop the to the deck. Preform the hoist, coil/flake any tail and back in the bag. Process is smooth. No lines tangled and under foot.
I find the mast bag a good purchase, worth the price on a cruising boat handled by a solo sailor.
If I was racing with crew, swapping sails frequently changing trim, I’d not use the mast bag. A different set of rules would apply. When storing the boat all the sails and running lines would be off the boat and in a sails & rig loft.