Everything I've reads says the opposite. Elden Ring has sold at least 13.4 million units so far[1], which is >$800 million in revenue. The only revenue figure I could find for Diablo Immortal is $800k [2]. They're not even in the same ballpark.
Until it doesn't. We're not talking about the same thing here because one is a one-time payment (license) vs on-going (loot boxes / SaaS). I'm highly critical of loot box (p2p) games, but you're on-going payments do pay for content in the future. Companies who charge once have very little incentive to maintain the software (assuming it requires it to).
Because Elden Ring took 4 years to develop, 5 years if you include the DLC release time. You would need to amortize its very front-loaded revenue over those 5 years, because a live-service game like Diablo Immortal would be generating somewhat consistent revenue throughout that entire time.
Let's say ER reaches 20M + 8Mx2 for it's two upcoming DLCs @ $40 each. That's $1.8B lifetime. Pretty amazing! DI would need to make $360M per year to be an equivalent business. So 800k in the first 24 hours is not too far off track to being equivalent.
We should be mindful of the biggest difference between Elden Ring and Diablo Immortal - the latter has a constant revenue stream via its in game microtrasaction capability.
Whereas the former, despite being a good game, may not provide the revenue model desired by its stakeholders.
Elden Ring isn't going to be a standalone game. The publisher (Bandai Namco) says it's the start of a franchise, which fans are almost certain to lap up for a long time to come. Had Elden Ring included microtransactions or other questionable features, it's likely fans would be far less enthusiastic about future installments, which means revenue from the franchise would dry up faster.
Someone made a video that imagined changes a company like EA or Blizzard might make to Elden Ring, charging for extra arrows, fees for questlines, microtransactions for boss assists, and so forth. It made me feel sick. I could totally see a marketing-driven game studio making similar decisions.
ER impressed me so much that I bought three earlier titles from From Software, an additional $120 spent. Regrettably, you show consumer behavior like that to a mercenary games industry exec, and they'll just see "lost opportunity to put the screws to the market" and not "we should make better games."
(This is the first time that I've literally worn out a controller playing a single game).
It seems like a good example to me. It was a sales model that worked. That's all. It doesn't have to work better than every other sales model out there. It just has to be profitable and successful on its own.