Everything in life has two sides. Night and day. Up and down. Good and bad. Exercise and relaxation.
In order to be fullfilled and grow you need both. Most people only pick the good things. Probably they only see that on the internet and hear that from other people. There you only see the results, not the hard work or discipline behind it.
It takes time
Similar to getting a taint in the sun. If you do a lot in one day, you will get a sunburn. If you exercise to much you will get muscle ache and do other damage to your body. It takes 30 days to form a habit. You will need some discipline for a few weeks. Then your body gets used to it and you even want to exercise.
Goals and keeping track
How do you know if what you are doing is the right thing and is working? You won't probably see much in the first few weeks. Like loosing weight. If you eat less you will loose water first. Even a few kilos in two weeks. And then nothing happens.
Even if people tell you that you will feel good when you integrate exercise in your day, you would have to have a strong belief in order to keep going. There are a lot of apps which track fitness progression. It's all external though.
How would you feel if you were fit? How would people look at you? What would they think? Should you tell others that you now start to exercise or do it in private and let the results show?