Notebooks are not typically used for long-term computation-intensive tasks. It is reasonable to optimize for small bursts of CPU power, as Apple is doing. Better cooling would negatively affect size and weight.
For typical office stuff, CPU performance simply doesn't matter. I'm currently using a 2014 MBPro and a 2019 MBPro. Theoretically, the latter should be orders of magnitude faster. In practice, I rarely ever notice a difference.