Nyeehh.... kinda-sorta. Lasers have advantages, primarily the fact that they're continuous fire and run purely off of electricity, but they also have disadvantages. Sean made a Spektr FEL laser rifle, which has infinite ammo, and can vary the wavelength (and therefore is actually capable of suppression), but it costs five tokens, and takes a second or two to actually do significant damage. While PW will sometimes describe low-power lasers lopping off limbs, that's just cinematics- in laboratory conditions, lasers need to be slowly and deliberately swept to sever things. Also, lasers are practically worthless against heavy armor, like battlesuits. A Raduga heavy FEL takes several minutes of being held on the exact same spot to get through a Battlesuit's armor, and costs eleven tokens.
On the other hand, a Testament has 180 rounds, which is more than you should really need. It can instantly kill a man with one shot, and can get through most infantry armor with a large volley (although it won't ever kill a battlesuit without several spare clips, and a lot of time). On top of that, it only costs four tokens, slightly cheaper than Sean's FEL.
Now, once you get into stuff like the PEW, then yeah, energy weapons are the best thing against the UWM, since they're all infinite-ammo. But the PEW is bleeding edge tech- we literally haven't finished the design, and the concept itself is a few weeks old. If we had people working on equivalent ballistic tech, then we'd likely have something even better than it. Also, to be fair you have to compare it to the armor which was just developed, and then you realize it isn't an end-all weapon: Hexsand is immune to it.
Really, if the UWM starts copying our tech, heavy weapons like the PSL and PEW will die off. It will be impossible to one-shot anything heavily armored, so you'll need a combination of kinetic and energy weapons. Heavy weapons, if they exist, will likely end up like Nikitian's three year old combi-weapon designs: literally a laser strapped to a gauss rifle.