Cisco does some world leading hardware and for those on the few teams still doing it they’re building world class skills. There aren’t many alternatives.
Cisco does some world trailing software and bug “fixing” (I’m being very euphemistic) ancient code in an ancient language where no one actually knows how to develop concise well designed and written code is the antithesis of what you want in a career. Smaller companies where you can take on a broader set of responsibilities is a much better place to be if you’re self motivated enough to keep learning and growing, but if you’re at Cisco in your 30s that may no longer be an option. Watching Youtube videos from high titled talent at FAANG makes it clear many of those companies have a lot of incompetence which further points to smaller companies.
I remember when IT saved a few pennies with cheaper NAS devices significantly increasing the already multi-hour build times decimating engineering budgets, and given the never ending network and phone problems (odd given Cisco’s business) there have to be better options to grow your skills.
Then you have sales, marketing, procurement, production, facilities and other careers where the tradeoffs are quite different from those above. At the end of the day Nirvana Corp. doesn’t exist and it’s up to you to figure out how you want to grow your career, and that will dictate which companies are best for you.