I suspect this is a "small company" problem which don't sell too many different things. A larger enterprise might have a platform for connecting businesses with businesses and businesses with customers. They might sell services (subscriptions) but also one-time purchases which require different forms of revenue recognition. Those might even be split up across different revenue streams. You end up building sub-ledgers for each one of them because the ERP can't handle the scale. Oh, and you're a public company so make sure everything is SOX compliant and easy to audit. Ah, and you operate on a global scale so do all those things in different currencies for different legal entities.

There's a reason Stripe is as successful as it is. And then there's a world where a company outgrows Stripe.

There are worse career choices ("prompt engineer" LOL) than financial engineering.