Why did Shadowrun add magic to cyberpunk? Because without it gameplay is pretty much limited to hackers (rogues) and mercs (fighters).
Honestly, Shadowrun plays almost identically without magic, because magic essentially functions in Shadowrun as a Measure/Countermeasure. You need magic because the other guys have magic and if you don't have magic, you're boned. Given how advanced the technology was in Shadowrun, and only got moreso as the technological revolution of the 90s and 00s showed us just how much was possible and the gear and cyberware tables expanded because of it, you can run Shadowrun entirely as a Cyberpunk experience and be able to do most of the same things. I mean, this is a universe with explosives, drones, nanotech, infrared and sonic imaging, neurological acceleration, etc. What does magic do that technology doesn't, other than add an extra chapter of rules? You forgot about riggers. They're basically Robot Mages, summoning semi-autonomous killbots instead of elementals and taking people out with stabilized flying sniper rifle platforms instead of manabolts. But the second all of your opponents are "mundane," all of your mundane gadgets can be used to defeat them. The only thing you "needed" magic for in Shadowrun was to kill all the things that were immune to your non-magical stuff.
Magic was only added to Shadowrun to create a niche for the game and attract conventional fantasy gamers. This was the late 80s. The game space wasn't very broad and they were trying to snag D&D players.
Eliminating magic/Tolkein from Shadowrun actually improves its gameplay, from a strictly mechanical perspective, because it simplifies the ruleset and levels out the power curve. The latter being especially notable because you no longer have to worry about Troll Physical Adepts destroying small armored vehicles with a bow and arrow, while withstanding shots from Panther Assault Cannons that turn the other PCs to paste. The classic "How do I hurt the 6 Toughness Dwarf in WHFRP without slaughtering the rest of the party?" I mean, I
get that the fantasy elements of Shadowrun is what appeals to a large amount of the player base, so I'm not suggesting there is a right or wrong way to do it. But Shadowrun isn't a great analogy for D&D combat. There's so much more variety to the ways you can play Shadowrun than how you can play D&D, so many different kinds of tactics and approaches in terms of how combats are run. They're just entirely different conceptual monsters.