>Counter-Strike, Team Fortress, Natural Selection
These games used the GoldSrc engine. Any game built on this engine gets called a mod. But this is not what most people actually think of when people are talking about mods. Rust is not a mod of Unity. These are game engines that people built a game using.
>DotA
This was a custom map. Not a mod.
>LoL, HoN
These were built on in house game engines and were not a mod.
>PUBG
This game used UE4 and was not a mod.
Calling DotA just a custom map is a bit of a stretch. That was merely the packaging. These "custom maps" had various scripting capabilities that made them more than just some terrain.
Also custom maps are mods by definitions anyways, with the exception of games where the creation of maps is a component of gameplay.
Dota is a wc3 map but, pendanticism aside, there is no distinction between a "map" and a mod in this context.
I like how you keep doubling down, and people keep destroying you. Please keep going. It is very informative for me to watch people correct you.
Counter-strike was definitively a mod, you had to install it in the same folder as Half-Life and start it with 'hl.exe -game cstrike'. It became a standalone game later with the retail release.
edit:
https://developer.valvesoftware.com/wiki/Counter-Strike#Vers...