I feel this description overstates the freedom. Academia is full of rather hard deadlines, as the conference you're targeting a paper for might be the only fitting one for many months. Missing these deadlines can delay the whole "pipeline" of research, as you'd like to build on your existing work and properly cite it, but publishing subsequent work might make the original result harder to publish. Grant application deadlines are similarly hard.

In contrast, deadlines in engineering are often even not expected to be hit.

The "freedom" to travel for conferences is an integral part of your job as a researcher: either you network and sell your ideas, or you stay in obscurity. Of course travelling on someone else's dime can be fun, but the same is true of all business travel. It stops being fun the moment it becomes a chore and you'd rather be home putting time into your hobbies or family. Then it's just more work.

If writing grant applications is your hobby and you're married to your research, academia can be great, but the freedom doesn't include a balance with all the other parts of life. I know I'm not fully contradicting you, there is indeed a lot of freedom to choose what you work on. I just think it's important that people considering academia understand what the job actually consists of.