Hi, I have three teens - 15, and 13 year old twins - so very much in the thick of the phase you're interested in!
I'm not sure they need you more as they get older, but they do need you more than you think they're going to when they're little. It's less of a physical need, but it's definitely harder work emotionally, at least some of the time.
Practically, in many ways our lives are much easier than they were when the kids were little. They can be left in the house on their own - at your kids' ages if I was taking one of them to something, I had to load all the others in the car etc. Two of them are perfectly capable of getting a meal for themselves/the others. They wash, dress, and organise themselves. I can ask them to go to the shop. You don't have that 'if we don't get dinner on the table by 6pm, the evening is going to be a nightmare!' feeling.
The things that I find harder: they go to bed late. This means the days of relaxing in the evening and feeling that your work is done are over (although they go to bed late, one cannot yet be trusted to brush their teeth, switch their phone off etc, so I don't switch off until last thing). I think this will pass soon, and they like the same TV as me etc, so it's not all bad having them there in the evening, but it is a change. Also, DH and I used to catch up with each other in the evening in a way that is often no longer possible.
Some of it is emotionally hard work - you're less able to fix their problems, some of the mood swings can be really draining, you worry about them (both for themselves way and bringing all your own unprocessed teenage-self stuff to it as well).
Overall, I feel positive about this stage of our lives, and for us, at the moment, it's easier than when they were little. But of course it's different for everyone.
I think the other thing, in your circumstances, is that your kids will be quite spread out - you'll be doing the stuff you're doing now and dealing with teenagers as well. I think I'd find that very hard (but I chose to have a very small gap of 18 months between my kids - though obviously the twins bit was a curveball!).