They concealed nuclear activity during the JCPOA. It may have slowed down there progress, but it was not stopping it. Afaik there is no non-weapon reason to enrich that far. They either wanted a nuclear weapon, or the credible threat of one to bully and black mail with. Its absolutely naivety to think otherwise.
The IAEA confirmed multiple times that Iran was complying with the deal until the US pulled out:

Iran is Implementing Nuclear-related JCPOA Commitments, Director General Amano Tells IAEA Board
Iran is implementing its nuclear-related commitments under the Joint Comprehensive Plan of Action (JCPOA), IAEA Director General Yukiya Amano told the Agency’s 35-nation Board of Governors on Monday.
The higher enrichment only started after the deal collapsed.
And yeah, there's no civilian reason to enrich to 60% or more. That's exactly why the JCPOA limited enrichment to 3.67% and included constant inspections. The point wasn’t to trust them. It was to cap their capabilities and verify everything. And it worked until we walked away.