Not just significantly weaker. The Librem 5 uses the Cortex-A53 low-end ARM designs from 2012, and that particular NXP chip is not among the better implementations. The 3GB of RAM is anemic and becomes a greater restriction as time goes on. Many features simply haven't been implemented (most of the sensors) and those that have been that are technically difficult (i.e. camera) provide only a bare experience.

If we're honest about it, the Librem 5 is not something to use as your main phone, it's a toy to experiment with.