The standard process goes: look at portfolios, make a shortlist of three, contact them, discover that two are booked until February, and hire the third by default.
You did not choose the third person. You were assigned them by a calendar you never looked at.
Why this happens
Portfolios are public and availability is not. Every directory, every awards site and every personal site leads with the work. Almost none of them tell you when the person is free, which means the most decision-relevant fact in the whole process is the one you discover last, after you have already formed a preference.
Forming a preference you cannot act on is expensive. It makes the person you can actually hire feel like a compromise, and that feeling colours the whole engagement.
Reverse the order
Filter to your discipline. Look at who is open in the window you need. Then look at the work.
Two things happen. The shortlist is shorter, which is a relief rather than a loss. And every name on it is a name you can actually book, so the comparison you are making is a real one.
The window is a design decision
Most briefs treat the start date as fixed and the person as variable. It is worth asking whether that is true. If the three people whose work you actually want are all free from week eleven, and your project has no hard external date, moving the start by five weeks costs you nothing and changes who builds it.
Conversely, if the date genuinely cannot move, knowing that on day one stops you wasting a fortnight courting someone who was never going to be free.
What availability does not tell you
Plenty. Someone open tomorrow may be open because they just finished a long engagement and turned down the next one, or because nobody wants to work with them. The calendar narrows the field; it does not pick for you.
But a narrowed field of people you can actually hire beats a perfect shortlist of people you cannot.
The sequencing problem
If you need two disciplines — a designer and a front-end developer, say — check both windows before you commit to either. Two crossings eight weeks apart is a project plan problem, and it is far cheaper to discover it now than after the designer has started and the build has nobody waiting for it.