If regulators instead went after service pricing abuse, that would force companies like Apple to drive down their repair prices—which might force them to design their hardware in a more modular manner, but not necessarily, so that if it becomes negligibly cheap to manufacture and replace the entire part of a less modular architecture, then they still have the freedom to design electronics in a less modular architecture. Repairability, considering the arbitrariness of the level of modularity that it stops, really does seem like a constraint on innovation.
User-serviceability is another unnecessary requirement, in my opinion, and in this regard, regulators can go after service availability. Electronics manufacturers who insist on tight integration of their products should make their repair services highly available, which seems like a fair trade-off.