My and my dad’s trip so far, and how to improve it

Me(30) and my dad(66) are currently on our 7th bike trip together. We see a lot of potential for improvement on this trip in particular, so thought I would sum it up for you guys, and maybe you could share some insights.

Previous trips have been to Samsø, Bornholm, southern Denmark, Northern Germany, and some of the Netherlands.

This time around, with both being busy, we had less time to plan the route beforehand, than we've had previously.

We knew we wanted to visit Utrecht, and that we wanted to do the trip on E-bikes, and with focus on a leisurely pace. We also wanted it to be maybe 60/40% Germany/Netherlands, and spend 10 days on the trip in total.

Day 1) Düsseldorf – Wuppertal (approx 50km)
We decided on flying from Oslo(our home) to Düsseldorf.
This decision created some problems. We immediately got unlucky, as our initial reservation for E-bikes fell through(literally the Seinfeld episode where the rental place had gotten the reservation, but didn't know how to hold it(which arguably is the most important part)).
So we rented from a smaller place. Renting everything in a city where bike touring isn't a big thing left us with suboptimal bikes, as it was first when we reached Wuppertal that we learned the one bike could only be charged from the bike itself, causing issues having to carry the bike inside to a power outlet every hotel/airbnb we stayed at.
I also realized that I had just adopted my dad's preferences, as he loves the bikes where you sit very upright. I could have as easily chosen a more sporty bike, as being upright isn't as important to me.
We also rented bike bags, 2 of which were with straps instead of hooks, making bringing all the luggage to our room an effort.

The trip to Wuppertal was not great, with lots of heavy traffic throughout. We didn't really enjoy Düsseldorf, but Wuppertal was luckily a much more exciting and beautiful town once we arrived.

Day 2) Wuppertal – Duisburg (approx 50km)
Here we finally got some nice, quiet bike roads, with a lot more forrest and nature, and were able to hold a high pace. But there was still heavy traffic here and there, the more peaceful country side was not yet reached.

Day 3) Duisburg -Kalkar (approx 45km)
This is where we really got into the groove we were looking for, keeping the pace nice and easy, stopping in Xanten for lunch, and also just stopping if we saw something cool.

Day 4) Kalkar – Winsen (approx 50km)
The trip was nice and with a stop in nijmegen for a trip on the pancake boat we were happy, but also tired and a still a bit frustrated with the poor start and planning of our journey.

Day 5) Winsen – Utrecht (15 km + train ride)
with a reservation for an airbnb in Utrecht the same day, we decided to bike back to nijmegen and take the train from there.

Day 6) rest in Utrecht.
Much appreciated. We got back some of the energy we have been lacking. Until now, every day ended with little energy to do anything, not necessarily physically exhausted, but tired from all the sun and the wind(is this normal? Does it ever pass?)

We are currently on our way back to Düsseldorf, taking some train and doing some biking as to make sure we have energy for exploration and having a good time together. But we both agree we kinda dropped the ball on this year's bike vacation, and are wondering how it could be better. I think choosing a area that's less urban, and picking an easier pace would do a lot, together with ensuring proper bikes and equipment.