I did a lot of bouldering and wanted to start doing lead climbing, until I learned that there's no independent certification for ropes.
The ropes in climbing are way safer than many aspects of the sport.
The thing that gives me pause over the last couple of years has been wondering about how picky I should be about partners.
Human error seems like the most dangerous part of the sport to me.
as for ropes.. just by from the "big" companies, beal, tendon, edelrid, mammut, pezel, they're all certified by the UIAA, just be careful and buy a "single rope" and not a half rope or a twin rope... oh.. and I recommend doing a course in your local climbing gym first for lead :)
There will be some really cheap stuff sold that absolutely does not meet the safety standards, and nobody with much common sense will trust or use these products.
But then you get reasonable priced items from no-name brands that might meet the specs, but nobody really knows, for all they can tell they might just just be unsafe junk just like the cheap stuff.
Since your life may quite literally depend on whether the product meets the safety specifications, is it worth going for the sanely priced stuff, not knowing if it is really safe, or pay for the overpriced stuff everybody knows is safe? If you ask somebody knowledgeable about the field, all they can can do is recommend the overpriced stuff.
Whereas if there was independent testing and certification, the knowledgeable people could tell you that it is fine to get any product certified by <insert certifying authority's name>, if money is not a significant concern, you can go for the trusted expensive but well established brands, but if your budget is tighter, the cheaper certified stuff is still fine, and won't kill you, but might have other minor downsides like not looking as nice, weighing more than the higher end stuff, etc.
the stuff to look for: ropes (EN 892:+A1:2016) in Europe carabiners/express sets: EN 12275: 2013, UIAA 121: 2018 "schlingen" (don't know the english word) for express sets: EN 566: 2017 belay devices: DIN EN 15151-1 , DIN EN 15151-2 (UIAA standard)
if you're in europe and want to buy a bit cheaper try decathlon, they have decent stuff from their inhouse brand "simond" and everything is certified and safe.
Otherwise.. just by from a decent brand, the stuff is safety critical.. so I personally would not cut cost with the gear :)
The need to overengineer things in the sport is quite interesting to me. I personally have tendency to use way more locking devices than my more experienced partners.
And I've replaced a lot of safe gear in my life just so my partners will feel safer.
To be honest, if someone shows up with a pile of mismatched draws and bootied cams I always feel way safer than when they show up with a nice shiny new rack.
One thing that's interesting to me is the difficulty of testing or inspecting things. I know plenty of people who find very old cordage or used gear in general to be sus.
I've tossed out plenty of two-decade old webbing and cordage that are perfectly fine and safe to use, just on the general principle that other folks might find it to be worrisome.
I also find most of the gear to be sanely priced; the reason the cheap stuff is cheap is because it skips an expensive certification process... so it's hard for me to call a $200 rope "overpriced". But then, I have a couple totems and was happy to pay what I had to pay for them.
What a lot of the discussion misses, and one thing I find super interesting, is that every time you climb you're dealing with used gear. And when you climb with a new partner you are often climbing on used gear of an unknown provenance.
The implication of this to me has always been that knowing how to inspect gear (and partners, HA!) and understanding all the real ways things go wrong is way more important and a much better use of my time than trying to get a deal from scoring un-branded gear.
My advice to folks is to read several editions of the AAC's yearly "Accidents in North American Climbing"-- that will tell you a whole lot (wear a helmet, back off sooner rather than later, be conservative when the stakes are higher, the gear itself is almost never the root cause).