im a bit before those games too, i figure you can make a game up to halflife 1 standard graphics wise as standard, and with shaders you can do better(I am not well versed with shaders but have seen their effects in example programs)
the rest is literally up to you, with clever resource handling and your own logic system, a well devised level of detail system and wise resource planning you can make anything you can dream up. It may not stand up to todays dx11 graphics but It will be your own game and made your own way, and If DBProElite every happens it will be backwards compatable, so you can use you current logic system with newer technology. so we all hope.
long story short, dark basic pro is what you make of it. It is an immensely powerful programming language if you look into what it provides for you within its syntax. It is simple enough to program in to maintain creative workflow whilst building your logic system from the ground up intuitively and easily.
I personally swear by it.
just use it for yourself for free and see If it clicks with you.
The forums are here, there are many amazing programmers that browse the forum to help new users like yourself, everyone else helps to their own degree of understanding. we all pay it forward as we learn.
welcome to the community.
kezzla