I do however often work adjacent to SAP or have to integrate with it, and since I've been at this for a few years now, I've gotten to try a bunch of their stuff.
SAP's biggest problem is honestly just that they are absolutely terrible engineers, while they suffer from the worst Not Invented Here syndrome I've ever seen. They nearly always want to build their own thing instead of using something that already exists.
Do you want to build web applications that interact with SAP systems? Well, SAP uses OData almost exclusively for all of its backend stuff, and practically no one else uses it. This means all developer tooling, like libraries and such, are almost non-existent. So what do you do? You use SAP's UI5.. which is easily the worst-made UI library out there that anyone has ever built. It's technical debt personified.
No one knows UI5 except people who work in this business, so companies are forced to hire consultancies like mine, because no normal web developer has ever worked with it(nor would they want to look at it in their spare time). I can scarcely begin to imagine how many man-hours SAP has wasted on building out this gigantic turd, or how many hours they could have saved by going with, say, React, and instead building libraries and tooling around that.
This sort of thing permeates everything SAP does. Everything they do is some of the worst stuff I've ever seen.
But hey, it pays great money, and the company I work for has great benefits and lots of freedom. All other things equal, I don't think there are many tech companies out there that could offer me a more rewarding job. But that doesn't change the fact that observing SAP from close-up is like watching an on-going technical trainwreck that never ends.