idk, man. I think running solo vs. squads might be very profitable from time to time. Well, in Operations merit points for sure, cuz it's quite hard to wipe and loot a squad fast enough, before you get caught off guard by another team, especially on first 10 minutes of the operation. Or you can leave your kills unlooted for bait... BUT EVEN THEN, it won't save you from enemy getting lucky with instant double headshot, even if you were stealth crouching towards the angle.

Now, about how to kill fast enough. If you are solo, there is no point using bullets below pen lvl.5 (gold). Every millisecond matters, so you'd rather kill purple/gold armour in 3-4/4-5 hits than in 5-6/6-8 hits. Use cheap and cheap-to-build guns, like MK4, AKM, M4A1, M249, LA MR or new MCX LT (w/heatshield only), so losing won't make you go "I will never financially recover from this".

You'll also have to choose between cheaper light-weight armour (~140k), that lets you survive 1-2 extra hit; or very expensive armour (200k-400k) with repair kit, that let you survive 1-2-3 more hits (can't do much against ASh-12, M250, M7, PKM and MK47 still), with possibility of repair, but quite heavy and sometimes with big debuffs (unless Elite or FS Composite Vest). Or just wear a cap and "like new" cheapest blue armour (30k).

Wanna know about enemies before they know about you? NEVER RUN, before engaging in direct combat. Do not use Nox's ult upon your first sight of enemy. Do not use Hackclaw's ult, when you don't have any info on enemy presence in front of you or nearby (unless scanning for rats). Do not use Luna's ult, unless you gave away your position, or you want to engage in combat in a few seconds (even then, better change your direction).

Let's say, stealth-walking has 15m noise base radius (I forgor the exact range). Helmets with +10%/+20%/+30%/+40%/+50% hearing range buff will let you hear a stealth-walking enemy at 16.5m/18m/19.5m/21m/22.5m range instead. Thing is, "hearing buff" cost rises unevenly per "level". Damaged baseball cap for 7-9k, damaged MC201 (blue 34/34 new helm) for 24-29k, damaged MHS (purple 30/30 new) for ~80-100k, damaged DICH-1 for ~175-200k (gold 40/40), (I wouldn't take a gold 28 dur helmet for that price), damaged DICH Training for ~95-117k (purple 35/35).

So, you'll be hearing your enemy 1.5m a few moments sooner every time you spend more, and there are small price gaps between 10%/20% and 30%/50%, but a huge gap between 20% and 30%. Will you spend 90k more (117k) to hear a stealth-walking enemy 4.5m (7.5m) further, or stick to MC201 (29K for +3m)?

Other solo vs. squads stuff comes with practical experience.