Relying on an obviously unsustainable free plan to build something always felt icky to me, because it will inevitably break, and then you will have to deal with the fallout of a perhaps now-unsustainable project of yours, your investment upon which then could end up possibly sunk, leaving you worse off than not having started the project in the first place.
Paradoxically, a lower free tier makes me a lot more likely to use Gitlab CI now, since I now know they know their costs and limits, and from now on, not eating the cost for a future drop of the hammer in an undetermined timeframe.
In general in any SaaS business, the free plan usually is written off as part of marketing budget.
The idea is that instead of paying Google/Facebook to display adds in the hopes that it will convert people as leads and hopefully down the line as a paying customer, it's usually much much cheaper to provide a free plan instead, which helps out as a "trial" of the final product.
Despite the sales factor, it also helps you get real users early on which can provide invaluable feedback to you, and help you prioritize the parts of the software that has real need versus what you imagine that people would want instead.
Paradoxically, a lower free tier makes me a lot more likely to use Gitlab CI now, since I now know they know their costs and limits, and from now on, not eating the cost for a future drop of the hammer in an undetermined timeframe.