It depends on what your goals are. At Cisco, we absolutely needed to do E2E testing because we were shipping people physical devices that they relied on to work

It depends on what your goals are. At Cisco, we absolutely needed to do E2E testing because we were shipping people physical devices that they relied on to work as intended. We built automation test frameworks and reusable/configurable tests. We built labs full of equipment and time-sharing systems to keep equipment constantly in use. Quality engineers wrote tens of thousands of (mostly) no-code tests, that would each do tens of thousands of permutations of tests. We wrote new test tools and bought high-performance test gear. In the end, we were able to do via automated testing what it would have taken thousands more people to do individually. Your organization and product goals may be totally different and not need that level of testing. But if it is needed, you can do it. It's up to your business to decide how much to invest in it.