Why is Unity the most popular engine?

False. Being utilized in automotive, architecture, and movies is simply a byproduct of their investment into workflow, robust base engine toolsets, graphical fidelity, and likely marketing. Epic has invested in key areas related to game development, and as a result their product can also be utilized for other purposes. Archviz and Automotive design are afterall, just “games”. The fact is, if Unity was at the same level as Unreal in areas of importance, they would be competing in the same market spaces, and they absolutely are not. Name one single AAA titled produced on Unity. I will wait. Escape from Tarkov is probably the most beautiful Unity game, and it looks horribly dated versus what could have been done in Unreal. Beautifully decorated game though I will admit.

Secondly, it is important to understand that investments are relative. Epic is a larger company and as such has more resources to throw around in terms of man hours and capital.

Unity is a skeleton of an engine and no top tier professional company wants to be reliant on an excess of 3rd party bolt-ons and why invest thousands of man hours on core **** that can be had stock with Unreal. Do I even need to mention Source access?

What this guy says is very true. While I greatly prefer Unreal, if you have spent 9+ years developing tools and systems within Unity, it is likely a step back in workflow at this point. This is the situation for a lot of smaller companies as well. They have built up tools and workflows for Unity and do not want to introduce the change that would be involved in moving engines. However, you also need to ask yourself what is so important that you have developed in those 9 years. If you spent 9+ years building tools and editor extensions that are entirely unnecessary in Unreal (they already exist) then the only thing you would lose out on is the time it takes to learn the new Toolsets in Unreal. Ignore the whole “9 year” thing and be honest about this. It FEELS bad to “throw away” 9 years, but just because it feels bad doesn’t it’s a bad decision. You’re also not throwing 9 years away considering all of the functional experience and knowledge you have obtained over that time that will carry over.