Hello. I have OpenBSD installed on all of my machines, including my personal laptop that I use for programming, gaming, etc. I do dual boot with Windows due to terrible proprietary software I have to run sometimes, but that's not often.

I wouldn't say OpenBSD's support is very lackluster, if your laptop is >3 years old, chances are everything is very well supported (this is a bit lackluster, I agree). Nvidia graphics isn't going to work, but most laptops with Nvidia come with Intel GPUs too (then you have to mess around with Optimus and all that if you want the GPU switching to work). OpenBSD just uses the Intel GPU, which is fully accelerated and everything, so everything other than gaming should be ok. Watching videos online is good, if you're worried about that. AMD GPUs work well too in my experience.

I haven't been disappointed by OpenBSD, but that's mostly because I check through man pages to see if my device is well-supported by every OS I want to use before buying it. It's very possible that you might install OpenBSD and find out none of your shit works. I advise you to search man.openbsd.org to see if your devices are in a list of supported ones anywhere. Or if some really similar ones are, then your device will probably just work too. If it's something like WiFi, you can always pick up a cheap USB WiFi card.

Most commodity hardware is well-supported, especially since the developers all run OpenBSD on their laptops, servers and workstations and use it for everything. But still verify with the documentation if you can. Or send an email to the mailing list, misc@openbsd.org asking for help. Alternatively, search marc.info for "laptop" on openbsd-misc to get some help. For example, here is a thread with some good recommendations. That was 5 months ago, so some things have changed. For example, Kaby Lake now has graphics support.

Good luck with whatever you decide to buy.