Yeah I totally agree with your assessment. The Laser Rifle, despite being a level 20 weapon is SLOW and seems to cause very little damage compared to physical projectile weapons. Also, the cartridges are expensive and can't stack them??!
Plus I have now added the Plasma Cannon to my list of Fav Weapons, & the Rocket launcher now shoots Homing Missiles. The Laser Rifle? Still acts like a Party Lights shooter... It's like the Empyrion equivalent of Terraria's "Celebration" Weapon...