TL;DR: Here's a game that anyone can buy for cheap, learn quickly, mostly skill focused, with plenty of room still for improvement across the categories.
Titanic: Adventure out of Time https://www.speedrun.com/titanic_adventure_out_of_time
Example Run
1996 PC game with a modern release readily available (a bit flawed to the original, but otherwise speediest option). Story involves a British agent on board the Titanic sent to retrieve various items which help avoid WW1, WW2, and the Russian Revolution. Explore the ship, talk to people, find the items, escape with your life and the future in your duffle bag.
Runs range from 6-12 minutes, depending on the category, and are relatively quick to learn. Most runs come down to technical execution of the keyboard and mouse controls, so good for those wanting a game that focuses mostly on skill. Aside from one simple glitch (a badly coded stairway), there's nothing complex to learn.
That said, some RNG does exists in all runs, namely a fencing game (stab me quicker!) and a randomized smokestack climbing maze (easy to learn the patterns). Some categories do require the player to win an all-or-nothing game of blackjack, but at these run lengths, a loss is not too devastating.
Don't let will_pal discourage you! Our star runner may have snatched all the leaderboards, but many categories still have plenty of margin to compete for, and I'm sure he would appreciate the challenge and motivation to run some more. WR aside, we welcome all to give running TOAT a go. ;D
Please take a look and consider it for your next speed game. If you have any questions, feel free to reach out to me or join the Discord.