The main reason why I only want original connectors for the NES is because almost all replacement ones are crap that break down in mere months or damage carts with a death grip. Repairing a console to be functional is perfectly fine, I just don't want it repaired with poor quality parts. It's like with replacing save batteries in carts, I want it done right, not just have the cheapest leak-prone batteries taped in with electrical tape. Obviously new capacitors are needed for repairs, but these are made by various companies and you can easily choose quality trusted ones over the cheapest poor quality ones as they're all marked by the manufacturers and quality ones are well known among the people who use them.

Of course when you buy a used system already repaired you can't be sure how well the repair actually was performed. Lots of people when replacing caps in Game Gears and other consoles are starting to use tantalum caps instead of the original electrolytic type capacitors as tantalum ones have a longer life and won't leak, unfortunately the circuitry is designed to use electrolytic caps so when those tantalum caps eventually fail the console will be damaged as the circuitry isn't protected for that type of failure, it will damage irreplaceable chips when it fails. I know someone who told me he paid around $80 to have the caps replaced in his Game Gear with tantalum caps, I just hope in 20 years the system won't just die beyond repair. Atari 2600 consoles are around 40 years old now and are usually still working, I'm really hoping consoles from the 90's can still make it that long as well.

As another example, talk to car mechanics. There are plenty of cheaper aftermarket parts that they will gladly use as replacements as they're just as good or even better than OEM, like with brake pads and rotors. But they know certain aftermarket parts aren't good quality and will stick to OEM parts instead as certain aftermarket parts are junk and will fail quickly, leading to unhappy customers demanding the issues be fixed again. It depends on what needs replacing.

With original NES connectors, the various used systems I've got over the years have been cleaned by me with a certain cleaning kit I find better than the original Nintendo ones. How do I start my games? I insert the cartridge, press down, and press the power button. Games start up right away about 8/10 times, and when it doesn't then a quick adjustment and a reset usually gets it to start up. The few times it doesn't start immediately are because the connectors are worn or dirty on the cartridge I'm trying to play, I don't spend minutes struggling to get games to boot except for really poor condition carts that aren't just needing to be cleaned. I try to avoid beat up games like this anyway when possible. I don't understand why so many people are still struggling with these connectors as they're far more reliable than the aftermarket ones.