but nowhere even close to as bad as say a ktm or husky.
My 2017 KTM 300XC has been the most reliable bike I've ever owned, and I've ridden it harder than any other bike I've owned. My friend has the same bike and it now has 500hrs on the original bottom end, with 0 major issues in it's life, as in never failed during a ride. All the KTM/Husky/GasGas that people I ride with own have been issue free. The idea that KTM is unreliable is about 10 years out of date.
Sherco and Beta have had some issues, but gotten much much better in the last 4-5 years.
Honda are reliable when ridden within their limits. If you take an air cooled trail bike with crappy suspension and brakes on a hard enduro ride or a fast desert ride, you would start breaking things because they are not designed to be ridden that hard. Honda does make racier models, but in my opinion nothing that is legitimately a good enduro bike. They are only interested in motocross when it comes to racing. The CRF300F would be an excellent choice for what OP described. And yes, faster than a DRZ or XR, not that anyone is trying to ride these bikes "fast".
Yamaha make an excellent bike, the best Japanese brand in my opinion. Extremely reliable, very high performance, and more focus on the off-road/enduro market. The two I've owned were excellent, some of the best factory suspension out there (aside from KTM). A friend has a TTR 230 that has been put through hell 5 times. We call it Timmy because it's so handicapped now. We have absolutely abused that bike, and it runs and runs. Also have done some very hard trails with it, and it has made it through. Extremely comparable to the CRF300F, except not EFI, less displacement, and 5 speeds.
Personally, I'm done buying used bikes unless it's from someone I know and trust their maintenance and use patterns. I've spent too many hours fixing weird problems and undoing "custom" tuning done by previous, misinformed owners. And, bikes bought new and maintained well resell very well. Ends up the same cost or cheaper over time, and you ride a better bike.
So, when people are comparing a brand new CRF300F (5k) to a 10-15 year old 450-650 for the same price, you are comparing apples to rotten oranges in terms of reliability/useful lifespan. And people think just because a bike is clean and shiny that it's been well maintained. Wait until you replace the fork oil on a 10 year old bike that's never had it done... Or take out tubes that are so old and dry they just come apart in your hands. Or discover that every wheel bearing and suspension bearing is rusted out because somebody rode the bike through saltwater or caustic mud 10 years ago and didn't clean it properly. Or the kickstart teeth shear off on your second ride. I could go on, and on, and on....
And now let's get to riding technique and how much bike you need to "go fast". The parallels to shooting are many. Suffice it to say, if you aren't standing up when you ride, if you don't know how to lift the front wheel using your legs and the suspension, if you can't balance on the bike at low speed or stopped, if you can't do a basic double blip over a log, then you should not be worried about the difference in performance of a 300cc bike vs a 400cc or 650cc. And these big displacement bikes will actually hinder your learning and cause you to develop bad habits. Sound familiar?