The Empire's tactics (and 'tanks') make no sense

Let's check what the Empire had the last time; a MOON-sized 'Death Star' that can explode planets quickly. Wow!

That kind of technological level must've taken ages to develop, right? When we think of weapons evolution, we probably start with rocks and sticks, move on to swords and spears, and so on until we come to the modern weaponry of guns, tanks, missiles and other realistic stuff (we'll forget the 'official story' claims for now, as they can neither be proven nor disproven, although the story has claims of physical impossibility, as in 'melting eyes').

From there, we can assume, The Empire's weapons research and development plus manufacturing ended up creating some pretty impressive 'light-based' stuff, although why light-based bullets would move SLOWER than the supposedly more primitive metal bullets, I can never understand.

In any case, inbetween 'metal bullets' and 'Death Star Ray Weapon'..

(which doesn't require a whole moon-sized facility/structure around it, now does it? Why couldn't they just build the CANNON itself and forget the megalomanic moon manufacturing?)

..there MUST have been similar progression as from rock to slingshot to bow and arrow to gun and so on.. right? RIGHT?

So they have this amazing cannon that can shoot a really powerful burst of energy in ray form throughout space for probably hundreds of millions of kilometers, but if they LOSE that particular, super advanced weapons, they..

..have to resort to those clumsy, badly designed, slow, massive 'walker' things?

WHAT?

Compared to just 'modern day' weaponry, even if we forget that F-19 actually existed as a superior stealth fighter, if we only think about 'conventional' weapons, this planet has superfast jet fighters, air-to-ground missiles and BOMBS (!), cannons (even shown in this movie), rocket launchers, tanks, attack helicopters, ground troops that can be dropped (deployed?) from a plane or helicopter to ANY spot on the map easily..

..The Empire has slow-moving, massive, easy-to-spot-from-kilometers-away type tanks that can't shoot very far, and that can be easily disposed of, and that actually would break the physical laws with being massive and heavy, and thus needing ENORMOUS amount of power to move their slow-inertia 'legs'.

What's the advantage here again over the things I mentioned?

Also, surely - SURELY !! - something as powerful as The Empire, with the destroyers that never destroy anything, have heard of and applied something called 'ORBITAL BOMBARDMENT'. Surely!

How the heck do you go from these stupidly clumsy and downright useless 'walker' things to 'being able to destroy a planet from hundreds of millions of kilometers away with one ray blast' without having SOMETHING more advanced and tactical inbetween, than slowly-moving 'walking things' that make no sense anyway, but especially considering this 'tech progression'.

Did The Empire NOT evolve their weaponry through 'tanks, airplanes, bombing, missiles, drones' etc. until they finally arrive at that massive cannon and 'Death Star'?

Did they skip a few step between 'completely useless, slow tanks deposited ridiculously far away from the target so they can slowly and cinematically creep towards it' and 'Amazingly Powerful Advanced Ray Cannon that can destroy a planet almost instantly with one ray burst'?

My point is, any group, entity, system, government, country, planet or entity that has vast armies, massive destroyers, and can build a 'Death Star', shouldn't have to revert to such stupidity and clumsy, useless non-tanks and forget that 'orbital bombardment' is a thing, just because they lose their most advanced weapon.

You can't have The Empire be powerful, menacing and have the most highly advanced weaponry at the same time as you show them being clunky, clumsy, having no air force, no bombs, no long-range cannons, and no orbital bombardment that would've destroyed the rebel base with precise strikes without anyone having to go on the surface to slowly die.

None of The Empire's tactical or weapons-side make any sense, as they're shown to be 'competent' and 'extremely incompetent' at the same time. I hate when movies do this just because it's 'cinematic' or something - someone should've at least given The Empire some TIE Fighters, so they could've shot and .. wait, don't they actually BOMB the asteroid later in the movie?! What gives? Why no bombs in the Hoth battle? WHy no orbital anything? Why no missiles, rockets and such that would've destroyed the base instantly?

NONE OF IT MAKES ANY SENSE!