There are some things which I don't have time for. I could not walk 100 miles a day. I could not read 100 books in a day (well, maybe kids' books).
But have you noticed that when people say “I don't have time to” they are never talking about activities that are actually, physically, impossible to find time for?
“I don't have time to...cook, exercise, read, keep the house clean.” But other people do all those things. Do they have more time than you do?
A variation is to extend “I don't
have to” to pretend that literally no one can do the thing. “I
don't understand how anyone can work full time and still find time to
cook.” Or: “once you have kids, you won't have time to exercise.”
These lines always trigger me because they are so obviously
false. Look around you and you will see many examples of people who
work and have kids and still manage to do X.
(We have a
cultural taboo about talking about success, so the people in your
life who actually do do the things might never tell you about it,
unless you actively ask. [I'll tell you, but I have no social
skills.])
So why do people claim that things they want to do are impossible? Partly because they don't have successful role models. Partly because it palliates the pain of failure. “No one with kids has a clean house.” “Of course I'm fat, I'm an American haha.” “Only rich people can save money.” Stop doing this. To invest in convincing yourself your goals are impossible is to commit to failure rather than success.
To steal a line from another domain: you have time for anything, but not everything.
Note that I am not telling anyone what to do. You understand your own circumstances best, and I don't have the information or the right to tell you what your priorities should be. If you've looked into the costs and the benefits and you're happy not exercising, not reading, or whatever, that's fine with me. I hear TV is great lately.
What I want readers to get out of this is the understanding that their life choices are choices. Distinguishing between a choice you are making and a fate you have to accept is surprisingly hard. It took me about 20 years to break out of that sort of learned helplessness. No institution, and no parent, really has an interest in helping you build an independent life—they want you to conform, consume, and defer to them. It's hard—but you have to build the life you want for yourself yourself.
To a first approximation, your life is not imposed on you by Fate. You choose what your life looks like.

