I would like to see strike craft be more fleshed out as a dedicated weapons preference, since the other three weapons types have a 5 tier main sequence, a 3 tier subtype, and a 2 tier subtype, but strike craft only have a delayed 3-tier sequence. Making them scale more incrementally by moving some of their tier upgrades to associated techs is one way to do that without needing to jam more techs into engineering.
This is a huge factor against Strike Craft as a weapon type, but then again, Stellaris also doesn't have warship Hangars until (wiki) Tier-3 Cruisers, T4 Battleships, and T5 Titans. Defense Platforms are indicated as a Tier-0 (starting) tech, and they have Hangars available, there are only non-Tiered Scout Wings. T1 Basic SC and T2 Improved SC are only usable on DPs and Starbases, and T3 Advanced SC are already the best standard SC available to any warship type Hangar.
There are Amoeba Flagella and Swarm Strikers as SC subtypes, but one is a non-improvable Tier-2 salvage tech and the other is an uncommon Tier-5 salvage tech. If there was both a clear opportunity for nearly all stellar empires to salvage the Amoeba tech and then the ability to create improved and/or hybrid Flagella at T3 and T4, that might be a useful 3-tier alternate SC. The Strikers are actually too far along and too uncommon to be part of a peer development path to Kinetic Batteries/Artillery or Proton/Neutron Launchers (BTW, what is the equivalent to those now for energy weapons?).
First thing to make SC progression look more like Kinetics (5-tier Mass Driver, 3-tier Autocannon, 2-tier Kinetic Launcher techs, and also non-reliant on salvage techs) would be to have them available in warships no later than Tier-2, by offering a bow section on Destroyers with a Hangar. (Perhaps better would be offering Destroyers at Tier-1, including the bow Hangar, but small steps first.). Second would be revising the progression from a clear Tier-0 starting SC to T1, T2, and T3 versions, and finally a T4 - these would be the standard hybrid fighter/bombers like we have now. For the first subclass, you could go with bomber-only variants (just 4 vessels, better suited for anti-CA/BB/Titan work, either doesn't or can't attack other SC); a second subclass could be gunships ( :cough: Gunstar :cough: ) that would be also limited in count per Hangar, but another hybrid and very durable. A different set of options could be a 3-tier "defender" progression (doesn't venture far from carriers, primarily focused on anti-SC work) followed by a 2-tier bomber set.
Of course, I have a ton of other ideas to expand and clarify the role of Strike Craft in Stellaris, but I don't want to derail this conversation too much.