I had this issue a couple of months ago. This became an absolute doozy for me... Let me run through a few of the things that I tried to solve this issue and then the annoying conclusion.
A little back story:
I've got an 11 plate CBR, brought second hand that was in pretty good nick, though it had been sat around for a couple of years when I brought it. It started fine when i went to visit it but I obviously did a full fluid change on the whole thing. For the first couple of months it would run fine and had no issues that I could find. Then it started cutting out randomly, even whilst driving. After a lot of bother and searching I eventually found out the alarm immobiliser had a recall notice on it: Datatool S4 C1 Red of a specific year. https://www.datatool.co.uk/safetyrecalls4/
After getting the guys to come out and fix that the bike ran fine... for a while.
Whilst I'd been going through the whole list of issues I'd replaced the battery, checked all the fuses, checked the relays, charged the new battery to full, removed the Kill switch and sanded the contacts, and checked the Bank Angle Sensor and the Kickstand Switch. After the recall replacement, everything worked fine... for a while.
A couple of months back the bike started to stall whilst sitting at lights after some hard A road/Motorway driving, and dropping revs occasionally whilst driving along, or sat still at 3k revs+. After the bike had stalled it wouldnt start again for close to 3 hours, minimum, doing exactly what your video was showing. Worst part was, I couldnt replicate the issue in the garage.
Again, started going through the motions, and a full charging of the battery was the only thing that seemed to cure the problem... I think. Basically I'd been overloading the bike with heated gloves and the alarm being a bit sensitive would occasionally go off during the night/day whilst I was away from the bike. I also mounted the alarm electronics package higher under the seat as due to the underseat exhaust I think the alarm electronics get too hot.
As for the relays, I swapped a couple of these out, but if they've never been removed from the bike, they can be tight suckers. I would usually put a pair of pliers on each of them in turn and try pulling them straight out, quite firmly. If i got one of the four out, and it wouldnt matter what one, then it would give me easier access to the rest.
Taking the problem as a whole, I'd say your best bet would be firstly, charge that battery. If possible get it checked for 'health' at a dealership, which shouldnt cost alot, and if its coming to the end of its life, get a new one. Next step would be to check out the alarm system, if any, you have on the bike. It could need a recall! If the recall had been more advertised for the Datatool I wouldnt have wasted a month without the bike. Third, check the Bank angle switch and the kickstand switch. These can be bypassed and eliminate them from the problem. Search the forums for more advise on that. After that, if the bike still doesnt start the last easy check is whether the relays have gone. It's unlikely but it can happen sometimes. Theres info on the forums for checking relays with a battery and a multimeter if you have one or can borrow one. Also, whilst youre under the seat check all the fuses. Just because.
Once you're passed these steps you get into more complex tests that revolve around fuel vs spark.
Fuel: is there fuel coming out of the tank when you crank. This means taking the tank off whilst leaving everything as connected as possible and seeing whether the fuel pump primes and pushes fuel through when you crank the bike.
Spark: is there something to ignite the fuel. Take a spark plug out and hold it near a grounded portion of the body and see whether a spark happens when you crank the bike.
These are the two only things you need to make fire, 'engine fire' that is.
Honestly, I hate electrical issues because they can be a righteous b---- to sort out and thats coming from someone who is happy to do pretty much anything mechanical to a bike so you saying your not that kind of minded, this may involve a trip to the garage, probably on the back of a trailer/inside a van.
Also, just as another quick idea, when you crank the bike, if you crank it for 10 seconds or more, you can get the bike to display the error code relating to the bike not starting. Something thats quite easy to check.
Hope you get it sorted mate, and keep us updated in this thread if you can. Always good to hear how problems get fixed.