It actually depends on the campaign. In my experience, in 2nd edition D&D magical items were very common in the hands of players with each player typically having like 10-15 items at any decent experience level. The problem was that ordinary people were still serfs and other stuff from the actual medieval era so you had the "Emrikol the Chaotic" problem - nobody could stop players.
In 3rd edition, the general feel has changed so that everyone and their dog can wield some sort of magic, directly or indirectly thorough items. Most players tend to have like 20+ magic items at any decent level, plus some spellcasting ability. It's the kind of world where if the players get unruly with fire magic in a bar, someone "breaks glass in case of emergency" and out of a glass bulb pops a water elemental who saunters over and smothers the fires then wallops the players.
Magelight appears to a be high magic world - where magic replaces technology. Technology is available to everyone, so if it's a direct replacement, there's going to be lots of "magic" (but would it be "magic" if it were common?) - so it's going to be more like 3rd edition.
This assumes that a magical universe has the same problems as our own. Stuff like "radiation" may not exist - being attacked and killed by something you can't see or fight against is thoroughly unpopular in all RPGs, let alone fantasy games. The solution could just be as easy as casting "Resist Elements - Radiation/25", "Vacuum Breathing" (a spinoff of Water Breathing) and "Permanency" on a suit of clothing. There, you can even have your stylish Poet's Outfit double as a spacesuit.
