I think you need to add that many more developers, or even teams of developers, are building these apps. They have their own fiefdoms and it's less common for devs to have a complete understanding of the code base.
Over time decisions are made independently by devs/teams which cause the code bases to get out of alignment with a performant design. This is exacerbated by the growth pressure. It's then really hard for someone to come in and optimize top to bottom because there is everything from a bug to a design problem. Remediation has significant overhead, so only things around the edges are touched.
Fast forward a couple of years and you have a code base that devs struggle to evolve and add features to as well as keep performant. The causes are many and we come to the same one whether we complain about performance or maintainability. You probably don't feel this way, but Stripe and other premier engineering companies are way ahead of others in terms of their practices when you compare with the average situation developers are facing.
Independent mobile development is often where I see most attention to performance these days. The situation for these devs is a little bit closer to what existed in the nineties. They have a bigger span of control and performance is something they feel directly so are incentivized to ensure it's great.
Over time decisions are made independently by devs/teams which cause the code bases to get out of alignment with a performant design. This is exacerbated by the growth pressure. It's then really hard for someone to come in and optimize top to bottom because there is everything from a bug to a design problem. Remediation has significant overhead, so only things around the edges are touched.
Fast forward a couple of years and you have a code base that devs struggle to evolve and add features to as well as keep performant. The causes are many and we come to the same one whether we complain about performance or maintainability. You probably don't feel this way, but Stripe and other premier engineering companies are way ahead of others in terms of their practices when you compare with the average situation developers are facing.
Independent mobile development is often where I see most attention to performance these days. The situation for these devs is a little bit closer to what existed in the nineties. They have a bigger span of control and performance is something they feel directly so are incentivized to ensure it's great.