You can't compare the two. A mobile game has a much different development structure compared to a Triple A game that is being developed for a multitude of platforms. This alone gives the developers of Destiny: Rising a lot of freedom because they only have to focus on developing it for the mobile platform. It's also a Gacha and those types of games are highly popular in Asian markets which means that it could potentially make billions upon billions. I've played Genshin Impact and DBZ: Dokkan Battle myself and those games make an insane amount of money compared to their budget. This in turn also gives more freedom to develop A LOT of content without necessarily needing to worry if you're going over budget. Bungie doesn't have that freedom with Destiny 2.