Here's a quick tip to make your left hand walking bass lines sound better on piano or keyboard:
Emphasize the 2nd and 4th beats. Lean into them a little more (they'll sound a little louder, but I don't think of it as really "accenting" them).
If you just play all 4 beats at the same volume, the bass line can sound a bit too classical, too much like Bach or Mozart for rock or jazz. By leaning into the "off beats" like a drummer would, you'll bring more of a "swing" feel into your bass lines, even though you're playing mostly quarter notes, not 8ths. Your musical collaborators and the audience will enjoy your playing more, without quite knowing why. Incidentally, this will sound great on piano or with a keyboard bass sound.
Just a little "sleight of hand" to help you elevate your playing. Have fun!
If you're interested, here are some ways you can develop a GREAT left hand piano technique: How to get a great left hand on piano
Take your left hand playing to a new level with my free ebook: Left Hand Techniques for Jazz Piano
You'll also get my weekly jazz newsletter with practice tips and inspiration