Domains are bought, not sold. The purpose of a landing page is to make it obvious to visitors that the domain is for sale. A landing page doesn't sell a domain name. You can look at some of the best portfolios and brokerages in the business for examples of landing pages that work, e.g:
Hilco Digital Assets:
age.com,
premier.com
Grit Brokerage:
aww.com,
oft.com
Perfect Domain:
fishy.com,
whe.com
The consistent theme is that the domain itself either is or redirects to the landing page. For content, they provide contact details, and sometimes the option to buy it now. Any content beyond that is based on trust in the business, i.e: here's why you can buy from us with confidence.
You have 2 options to sell a domain:
1. Sell to an end user who has decided they want your domain
based on the domain itself. Distribution is important for selling to end users, i.e: people should know the domain is for sale (and ideally, a price). Distribution means a landing page (ideally with a price) and posted on every marketplace (Afternic, Atom, Sedo, Spaceship etc.) because these domains are syndicated to registrars (e.g: listing with Afternic means someone search for "wwx" on GoDaddy would be shown your domain as an aftermarket domain for sale).
2. Sell to an investor based on the investor's personal belief about the long term value of a domain (i.e: they buy it from you to sell to an end user in future). An investor buys based on the domain name alone and will pay a fraction of what an end user
might pay (the difference is how they make their money).
End users = best price, longest time. Investors = quickest sale, low price.
You can make comprehensive landing pages if you want to, there is no disadvantage to it, but it will not move the needle. Visiting wwx.com should show that the domain is for sale, and ideally, provide a price, but beyond that, you're just having fun
If you want to move the needle, you need to focus on distribution and price.
