@qhobbes made some good points... I'm still on Win10, and avoiding Win11 while I can (my next PC, soon, will most likely effectively require it .argh). BUT, buying a PC that can't run Win11 means a short usable lifecycle, too short for me to consider for any purchase now.
If you friend needs a portable for good reason (and coming from a tablet, I could see being tied down to effectively a single location would NOT work for someone.) in which case.... a gaming oriented laptop computer probably makes the most sense (though personally I can't stand gamer RGB lighting, etc... you don't need an actual gaming computer... it is just that the high-level specs of a gaming computer will tend to match up well with real-time video encoding performance expectations). Microsoft's Windows 11 operating system was apparently released on October 5, 2021 vs Windows 10 release in 2015. The Intel Core i5-6300U released in the Fall of 2015, and Dell Latitude E7270 released in 2016, aren't a good fit for this use case. Further, Windows 11 can run on subset of hardware that is Windows 10 compatible (I haven't checked if that old Latitude is Win11 compatible... regardless, wrong config for real-time video work).
So... assuming a more recent generation and more powerful version of CPU/computer.
- To avoid needing a powerful CPU to do encoding, you'll want either an Intel CPU with QSV (as qhobbes mentioned) OR an nVidia dedicated GPU with NVENC. You will have more flexibility and power with NVENC. There is newer encoding coming with AV1, but that requires upper-end versions of latest generation hardware to encode... so I'm assuming out of budget range.
- Beware the long-battery life type systems (especially with U model CPUs, but even next level up), as they will tend to thermally throttle, meaning ok for short periods of compute intensive work (like using OBS Studio), but longer timeframes can and probably will be problematic... and some people want to Stream/Record for an hour or more... those two desires conflict. sort of a 'pick one, can't have both' scenario
- Aaron mentioned "If you must use a laptop, look at the "mobile workstation" class of machines. Or an actually-serious gaming laptop. Those are thick and heavy, because they DO have the thermal design to run at full throttle all day." Such machines tend to be rather expensive... and is what I'm looking to purchase right now.... BUT... can be overkill depending on exactly what the requirements are, and will be. The challenge is that once someone gets started, they tend to look to improve things (overlays, sophisticated transitions, green screen/chromakeying, noise suppression , compression, etc.... ) ALL of which add to CPU load. So, even if you accurately determine workload requirements (and these are unique to the individual, apps being run, those of with experience can only guestimate into broad ranges) those requirements can often increase over time. So your friend will have to know themselves well-enough to know if they would want to pursue such improvements, and then if they can afford the extra performance capacity now in case they end up needing it in the future. But if simple 1080p30 with simple static, limited overlays, single webcam is all that will be needed for 3-5 years... then an Intel CPU with integrated GPU may be plenty. But if real-time video work is going to be more than 10/15/20 minutes at a time, then really good thermal design (which gaming oriented computers tend to have) will be essential
Personally, I've avoided (and recommended others do the same) i5 and lower up until now... and even now, I'd probably still avoid it... but that is based on my expectations of paying a little extra now, and expecting 5+ years life (most of my PCs last just fine for 10 years... not doing computationally intensive workloads, hooked up to an auto-voltage regulating battery backup unit to protect PC hardware [not as applicable for laptops]) and not feeling performance constrained along the way. Realistically, some of the latest Intel i5s are plenty powerful enough for non-compute intensive workloads, I just have some other requirements which make them a poor fit for me.
So you have to balance available budget, expectations (usable lifecycle, etc) and performance requirements. Assuming desire for more than 2 years of life, getting a computer released with Windows 11 (so fall '21, and probably ok a little earlier with detail checking on specific technical details and Win11 compatibility... I'd check vendor forums to make sure any initial 'teething pains' with Win11 on that system have since been resolved vs a vendor that moved on and that mid/late 2021 PC was 'orphaned' /didn't end up with solid/stable system software.) If budget really tight, I'd go for an upper-end i5, and if enough available, I'd go mid-range i7. There are more specific ranges of systems, but such systems are outside my area of expertise, so I'll refrain from commenting further.
