Enterprise software is more willing to milk money from corporate than to leave money on the table. The amount of money a company is will to pay can be order of magnitudes higher than an enterprise software imagined. Hence SaaS company hire bunch of sales people/sales engineer to "understand your need", which is an euphemistic way of asking how deep your pocket is. And when everyone is doing this, you can't simply move on, there are only so much options.
Of course, you could see it completely differently, private pricing means longer sales process, higher labour cost and fewer customer. Having tiered offering is common. This is actually what gitlab did, free plan, individual plans, business plan[1]. If you don't need worrying about data residency, you don't need contacting their sales at all.
One more angle, when you are starting up, every bucks feel like coming out of your own pocket. When purchasing "enterprise plan", your company already attain certain size and you are spending your company's money, money that otherwise would not fall under your pocket anyway.
Or your startup is forced to look into "enterprise plans" due to necessary features for compliance being locked behind them, without having attained a certain size and "enterprise" money.
Of course, you could see it completely differently, private pricing means longer sales process, higher labour cost and fewer customer. Having tiered offering is common. This is actually what gitlab did, free plan, individual plans, business plan[1]. If you don't need worrying about data residency, you don't need contacting their sales at all.
[1] https://about.gitlab.com/pricing/