In spite of the branding, Phoenix Point isn’t an early access game, and was never meant to be: it doesn’t get regular updates, the mechanics included aren’t polished enough in terms of balance nor bugs to make for an engaging loop.
What you get is your backer beta thing, which is done often during crowdfunding campaigns to allow more passionate backers to give feedback, see some of the core mechanics, and most importantly, encourage chipping more money into the project.
PP continued selling this beta after campaign ended, which I understand (both from developers who want to push more pricey copied, and customers who want access to it) but dislike the post-campaign branding. PP isn’t fit to be an EA games - good EA games have very limited gameplay loop which can be expanded with content later on: variety of items, maps, enemies etc. PP has multiple systems and game planes which need to fully exist to properly work together. Those have been in development and were showcased via BB system as Devs wanted to gain feedback on them.
What your $20 covers is “prestige” of being able to play an early build and be able to have first-hand complaigns.
However, what you don’t play is the game as it develops. Those are separate builds made using some of the content they have for showcase purposes. Each backer builds drains resources from actual game, as this separate build needs certain amount of QA to be playable, and things that are fixed in it might not translate into Dec built which has moved forward. so it is understandable if they decided at this point to focus on final release. Even traditional EA games tend to freeze updates months before 1.0 release, and current planned deadline for PP is coming.