Engineering is about suiting the needs to the means. In the realm of widely-used webapps, the need is 1. speed to market, 2. features and 3. maybe stability against errors 4. if successful, scalability.
And our engineering is perfectly successful for that. We are able to output features after features, we’ve factorized the boilerplate, and we publish our apps before they’re even ready.
The idea that most software engineers can make any real guarantees about the correctness of their programs is laughable. At least once a month we hear about a massive new vulnerability that proves that that just isn't true. To not accept it is hubris.
It's not about calculating performance. It's about proving that something fundamentally fits in with everything we know about the world. Software developers that approach their work with this mindset are exceedingly rare, and their work is largely academic.
Software does exactly what you tell it. Hardware does what you tell it, but it always listens to mother nature first.
Cannot speak for EE, but I'm friends with people who do ChemE, MechE, Civil and mechatronics.
Additionally, the minimum knowledge required to be a "good" software engineer is significantly lower than the amount required to be a "good" electrical engineer. You are not pushing any limits without an expansive understanding of mathematics, multiple opportunities to work on some very expensive shit, and an employer that's actually pushing something forward. Getting a VLSI/radio electronics/DSP/etc. engineer online is a process that takes years before that engineer doesn't need constant input to keep them from shitting the bed. Unless you're so passionate about it that you can't possibly bring yourself to do anything else, you would have to be insane to go through the amount of learning required so you can pull a salary that will only slightly top an entry-level software development job.
None of this is to say that software development isn't valuable, or that the people that are doing aren't skilled, but as an industry, we don't hold ourselves to anywhere near the standard that other disciplines do, and there's not much to gain other than saving face by not admitting it.