Are you seeing this as well? What kinds of systemic issues do you think might arise from this sort of change? Have you, or your organizations, evolved any strategies for balancing operational complexity and information siloing against the perceived benefits of this kind of SaaS specialization?
Working on a search/review/ratings engine (https://tooltip.com), that currently operates as a consulting service, because I've found that parsing through all the muck is a waste of human time and anxiety (also, ppl often end up on the WRONG solution because they didn't have enough time or the right resources to search)
Edit: More immediate practical strategies are to use a spreadsheet that aggregates up from the dept level to the company level to keep track of all users/accounts, or buy a piece of SAAS to manage dedicated procurement / billing (there are a few alternatives out there on this front nowadays)