Sure, it lets you ship that app with postgres, clickhouse, redis, rabbitmq, task runners, workers, the jvm, 5 different versions of nodejs wedged in... But is this really a good thing?
Its like vacuum sealing poop in unlabeled bags and putting them into someone's refrigerator. Yay, surprise.
For me the real issue is that we still live in a world where many developers don't have anyone to hand that container off to. Even if your cloud helps you, you're likely still going to have to configure things like networking, and while I've done that myself because nobody else could, it really shouldn't have been something I did. The first time I did it, every application/service had 250 IPs despite using 3 or 4 and I'm fairly certain my vnet ate up like 50.000 IPs which I think you call a block? And as you can see, I still shouldn't ever configure network, but I'm still the best at it and nobody in management seems to want to change that.