Loved this post - for any others here who share similar views, thought I'd share a few thoughts from our experience working on this.

I'm co-founder at https://www.wanderant.com. We started off with similar frustrations on planning trips. All the information you could ever want is online - and for free - so we should better off than where we were when you'd just buy a Lonely Planet book. But that's not the case, I think it's actually gotten harder - partly because there's so much info, and so many options.

We're a year+ into it, and have been iterating multiple times on an MVP. It's a big problem to solve, so 'minimal' is a bit high - plus it's a different minimal for every traveler you meet (e.g. comment here on "an option for children" which is absolutely critical for some).

Here are some things we've learned along the way:

* Top 3 things people need / want that haven't been solved:

- Local expertise - esp when traveling abroad - what is the local yelp / gothamist / etc?
- Help with logistics - mostly around how to get from A to B - Rome2Rio is a great help in that regard, still takes a lot of work for planning an entire trip though
- A way to manage a plan in one place - instead of email /bookmarks / excel

* Some of the challenges we've encountered:

a- Making a product that's easy to use - If you're only solving one step (e.g., online booking), it's easier to create a workflow that makes sense. I love examples like how hipmunk have simplified UX for booking flights. We are building towards a workflow that lets you keep your entire plan in one place - ideas, map, notes, reservations,... and finding a UX to make that easy is a lot of work.

b- Getting to a product that really adds value to planning- We want a tool that simplifies the process of planning. However, we clearly can't start with a product that does everything you need for a trip. Even in the near future, our product will continue to be an incomplete solution. So paradoxically, by being an additive tool in the process, we've successfully worked against making it simpler :)
We have to make up for that by really adding a lot of value and saving time fr the user- and getting to that point is also a lot of work

c- Marketing is hard - others have mentioned the challenge of facing giants in the space- I'd like to offer another piece- which is reaching trip planners at the right time. Only a small % of people we reach are in the process of planning a trip. Then if they are, we most likely don't yet offer very rich content for where they're going - because currently our higher-quality content is still nascent. So that makes finding the right users hard. Any help here is appreciated btw - if you know someone who could use this send them along :)

* Why we're continuing
- Times like this, when we see someone get passionate about how much they wish this existed or how they can't believe it hasn't been done before. We feel the same :)

- While it's a hard problem to solve, and there's a lot of challenges we already know of and more we don't yet - it is a really interesting problem to think about and try to crack.

- More than all, we love to travel to new places and explore the world. If we can share that experience and make it easier for a few others, we'd be ever so pleased.