Warfare needs to be improved.
Replacing losses after big battles turn to a tedious clickfest as you have to build every single ship individually. Having a mechanic like in EUIV for armies where you set a specific number of units per type and letting them produce automatically at the nearest spaceport without orders/only at specific ones for cheaper production (for building up fleets as well as reinforcements) after taking losses. After setting a number of ships in the fleet it should be automatically reinforced until it has full strength again.
Also going down the road Star Trek New Horizons has taken : Less ships overall but each ship being more durable would be a very good improvement.
Everyone loves big space battles but Stellaris in vanilla has a big problem. They don´t look good unfortunately. Vanilla ships line up in an ugly planar multiline formation. If you have 400 ships massed in a single fleet it nearly spans half a solar system. So less ships and aranging them in a more spacy formation not only spaced on the x and z axis but also on the y axis. The Star Trek Total conversion did a great job with this.
Also making defensive stations more useful would be a big improvement atleast in my eyes. They don´t need to put out big amounts of damage but should be much more durable to bind enemy forces like fortresses in euiv.
Also an introduction of a shattered retreat mechanic after a lost battle would be more favourable than total obliteration after one spacebattle between two doomstacks. This would pair well with the less quantity - more durability ships approach.
I agree with all of this. The ships should indeed be able to take more of a whack, losing a ship should be a big deal, not just able to be thrown away. This would lead to being more emotionally invested in each ship too.
I mean at the moment you can rename all your ships....whats the point in renaming a corvette when it will be destroyed in the next battle?
This will also help with late game lag.