Activities and hobbies are great for your kids in many ways.

Keep your kids in activities!

Here's a short list:
Chess club
Football, baseball, soccer, basketball
Tennis, golf
Chorus
Swimming
Dance
Gymnastics
Piano or other instrument
Acting in a school theatrical production

Do know too that might not like everything. Once you get them into something and they don't like it, it's ok to stop and then try something else. If they're on a team that needs them, they should play out the season, but then they can try a different sport or something different altogether next time. Also, you may think your child should be in sports, but they may love and excel at singing. Or vice versa. Let them find their voice (pun intended).

Through activities and hobbies they will also make new friends, learn sportsmanship, teamwork, how to handle wins and defeats, and of course can keep them active and healthy. These are all things that can prepare them for the real world and grown up life.
And, if they work out all their physical energy doing these things, they will be better behaved and even sleep better.

Getting better skilled at various things will also increase their self esteem. They become more social and engaging and become more likable people. Those who let their kids stay inside all day watching tv or playing video games aren't doing them any favors. They'll be socially awkward, not even slightly athletic and be introverted and lack confidence.

Many cities have programs for sports and other activities that are free, or can be free by completing an application. YMCAs also have many events, teams, and lessons and they make membership pricing income based so anyone can afford it. Most schools also have chorus, chess club, band, plays many other activities that are not only free, but will be done after school but before you pick them up, if you happen to be 9-5ish.

To make things easier too, you can also team up with another parent to share rides if you have to work late, or can't go every practice for another reason. If you do go to all or most practices, make wise use of that time. When my son played football for the community athletic association, he'd have practices 4 nights a week for 2.5 hours each. This is a lot, but I would bring work to complete, call and take care of personal business, and I'd even bring gym pants and shoes and walk around the complex and get exercise while he practiced.
Be a team mom or coach, play costume designer, if you have the time and skill. Your kids will always remember that you were involved.