Experienced Developer / ex sysadmin here : short answer, they are bloated in every possible way and one reason is that software houses, developers, contributors, maintainers don't want listen users when they say: "I do not want this feature because I don't need it" so they do not give any power of choice to their users about disabling, deleting, removing, not installing features they don't want, they don't use or they make that possibility so hard to implement users desist.

Every time I need a new laptop I remove a considerable number of services and programs, I change when possible even the windows manager, I also change lot of default configurations that are useless and /or waste resources, cpu, battery, disk, network.

Also, that is useful for security reasons reducing the attack surface.

Taken individually software I remove seem harmless but, in reality, they are like zombies in large number they can eat you alive.

For example: voice control, this to explain the concept, I never use it, especially on my professional machine. Do you imagine people in an open space office, screaming orders to their computers ? But maybe a disabled person can depend on that feature so it's good to have the possibility to enable it but do you think it's acceptable that this is installed by default on your phone / computer / whatever ? "Yes, but it use only 0.6 % of cpu in standby, you are exaggerating !" Yes of course, it seems harmless ALONE but, of the hundreds of process now in execution on your pc how many are doing tasks useful for you ? On the other hand, how many are there because are installed by default, just in case you are in a small user of groups for that application ?

I observed systemd-oom on my machine using a fix 0.5% of CPU, I have 64GB of RAM and 4TB of disk, I oversized explicitly that computer for my jobs. Why I should need this daemon ? Oh, anyway, do you know how work con AIX ? you can reserve some RAM for emergency shell so, in case of OOM, you can take actions without a stale.
Again, "You are exaggerating, only 0.5% of CPU !!!". Yes, alone, but in this moment I have 560 process in execution on my pc: if 100 are bloatware, 50% of one core is gone being optimistic with related net, RAM, disk, battery, etc. Again, if someone find it useful, good for him, good to have the possibility to install it.

I would like to have a real minimal installation mode, where I can select explicitly what I want to install, in detail, plus, for everybody else a "premium bloat inflated mode" the install utility like scratch-my-back-d and every "just in case whatever" one could desire.

The number of that "inutilities" is increasing because someone think are required from a MODERN USER, but in reality, if it was still upgraded / updated, I could do my job with that very OS of 20 years ago, but at speed of light.

I remember that every time I use a VM with legacy software that's so speed I can't believe it.

We have start menu that search on Internet software to suggest you for installation, advertisement everywhere, telemetries , statistics, convoluted GUI with animation, effects, bullshit that don't add useful features. Simply they are here "just in case".

And about the programs ? Even worst: layer and layer of usefulness coupled with MODERN programming tools, paradigms, language that in the facts kill the performances.

About the cloud ? It's inserted in every possible useless / annoying way in functionalities that in no way take advantage from that.

Web app ? I'm sure that 10 years ago browsing was faster ! Same reasons.

The sad story is that at the end, in case of commercial OSs like Windows / MacOS you are paying for software, for hardware, for electricity that execute tasks you don't want and you don't need and, with few exceptions, the same jobs you was doing 20 years ago with XP are now slower. Linux ? Major distribution are becoming in indistinguishable from commercial OS, at least you don't pay for the software.

I'm listening more and more people saying: "I want to migrate to OpenBSD". Don't you ?

"Eh, but now you have wifi, ultra-mega-xd VGA, etc, etc".

Of course and also I have a 20 core processor, 64GB of RAM and a monster VGA with 8GB of RAM, 2 high-end NVME and still I had a 1/2 second lag after every key I press in my terminal, before I removed tons of bloatware from my laptop, full story here:

https://news.ycombinator.com/item?id=40110342

so at the end the status of modern OSs piss me off twice. Try to search on Google "Ubuntu 22 slow on modern hardware" or something like that.

I'm listening more and more people saying: "I want to migrate to OpenBSD". Don't you ?