...and then you woke up and realised that Iran never allowed those inspectors to inspect the actually important facilities and started removing inspectors from the country in 2023 under Biden.
Biden was elected _after_ Trump broke the deal so it's unclear why you think that tells us anything about what would have happened had the United States honored the treaty.
During the time of JCPOA (original, between Iran and the P5+1) inspectors had access to where they wanted to go (sometimes with friction, sure) and were able to place tamper resistant / tamper revealing instrumentation, air filters, and spectrometers - effectively creating a data record that could place a stochastic cap on {enrichment level, volume}.
After Trump ripped up that agreement during his first term, withdrawing from the pact in 2018, that was no longer the case - leading to your linked 2023 statement.