Hi, so I don't know much, only what I experienced myself, but very simply:
Hand-drawn art has (obviously) preceded digital art. Black and white manhwa was a normal thing because it was intended to be printed on paper. So not only the works of early 2010s but also in 2000s and 90s, this was very normal. Unfortunately, quite a lot of works was never fully scanned thus translated. Even on this page you can find so many great pieces that are unfinished forever.
Now in the late 2000s there slowly started a shift because printed copies didn't sell well. I wouldn't know the actual reason why that is but I suppose the circulation just wasn't as accessible and smooth as in Japan? Plus with BLs specifically, there is the regime's opposition. Anyway, so in 2010s this practice slowly transitioned into online platforms until the printed copies nearly disappeared.
The online space obviously invited colour and less "space saving" - long strip format (no longer the need to worry about printing price). These days it is common that popular serieses get also print copies.
Luckily, even now, some artists choose to draw in black and white, or in a similar style to the old works but it's less common. The digital art is just naturally much more clean and bright and coloured to fit the trends of current market.

Someone educate me on the era of black and white Korean manhwa that look like mangas. (i.e. the time these were/are popular.) Obviously I realized that you have this from left to right but I still didn’t register that it could be a manhwa until they mentioned Seoul…the same thing basically happened with https://www.mangago.me/read-manga/love_at_first_sight_season_1/ Manhwa being black and white I know common enough but I didn’t know there are so many 2010s(?) manhwa that look like mangas