This gets you a long way very quickly, which is proof that none of these principles really matter. Development continues along this path at a cracking pace for 6 months until complexity spikes and your productivity is at a crossroads. Do you take a step back, refactor, restructure so the code can be built on with any degree of velocity?
Hell no! Everyone's expecting the same output as when you started, so now you have to start copy/pasting everywhere trying to keep up, but your bug tickets have started ticking in so you have to address those. But you don't have tests, so now each bug fix raises two more bug tickets. Uh oh.
Better get more devs. Now you have people who don't understand the system making changes. There's no real structure so they just squeeze code in where they can, but progress is slow because it takes them five times the amount of time to reason about what the system does and bugs are still going out. Must be bad developers. Better hire a QA team to stop all that.
QA is reporting defects with each release candidate, and puts it back in the dev queue. After a year each feature is taking months to go out. The business just wants some simple changes, why is that so hard?
Enter the hotshot dev. They whip up a quick MVP with the latest language/framework plus it's serverless! No SOLID principles but that doesn't matter because the latest technology will fix everything. Better fire the old team and start fresh.