I think the approach makes perfect sense for the "digital age" and with the approach Damon has had for songwriting lately. Humanz had an extremely scrappy production that structurally resembled a Gorillaz-curated "playlist" that was mainly held together by its interludes, and a lot of the fictional band appeal was treated as secondary. You can tell just how much "material" they were pumping out around this time since it didn't even take two months for them to put out Sleeping Powder (which was written in three days) and for Damon to write an entire new album on tour with the sole purpose of having new live material. The last time Gorillaz ever attempted to approach more of a high concept album was with Plastic Beach which was such a moneysink for them and which put a strain on Albarn and Hewlett's partnership which soured them on the whole notion of making more with the band (which is a shame since that album's aged like fine wine). Instead we're back to the more scrappy self-titled days when Gorillaz was a big deal on MTV and when the album was basically a goof which was held up by smart marketing.
That said I agree that there's something much more "immediately gratifying" in getting an album that's structured, finely tailored and conceptually loaded, and it does make for more of a spectacular "event" release. Who knows if the experiment will pan out in the long run; it's possible that planned "second season" could end up just being an album. I know that when Nine Inch Nails worked on the Not The Actual Events series it was meant to be an EP series, but the Add Violence EP was less positively received/more troubling in production, and Trent was really annoyed at how EPs generally got shit for exposure (especially with services like Spotify burying them under albums), hence why they made Bad Witch as an album.
Things could change, but for the time being it seems Gorillaz are just content with putting out more material and having fun with it, which is really all I can ask for. There was a time I was concerned that Damon would rather work on Blur or any of the other bands that didn't require so much pre-planning, conceptualizing and budget. Establishing a "production company" that isn't just Hewlett's Zombie Flesh Eaters shows a seeming commitment to the band as a concept though, and it's not something I expected. Interestingly the Song Machine releases are licensed under "Damon Albarn and Jamie Hewlett" rather than "Gorillaz Partnership".