Why it feels like the only option
The equity is in the house, and the deposit for the next one has to come from somewhere. If the only route you know is a sale, then selling first is the plan, and the consequence is either moving twice or writing an offer that depends on your sale closing.
In a market with any competition, an offer contingent on selling is the weakest offer on the table. That is the real cost of this belief, not inconvenience, but losing houses.
What the alternatives look like
A second lien or a line against the existing property can release equity without disturbing a first mortgage you would rather keep, which matters a great deal if that first mortgage is on terms you will not see again. Short-term bridge financing can cover the gap between buying and selling.
Both add cost and complexity, and both are only worth it if the alternative is worse. Sometimes selling first genuinely is the right answer; the point is that it should be a decision rather than an assumption.
The honest trade-offs
Carrying two properties, even briefly, means carrying two sets of payments, and any plan that depends on the first house selling quickly should be tested against it not selling quickly. Bridge financing has a maturity date that does not care about your timeline.
That is the conversation worth having with real numbers rather than in the abstract, what each month costs if the sale takes longer than you expect, and how long you could sustain it.
What to send
The current property, roughly what is owed and on what terms, and what you are trying to buy. That is enough to lay the options side by side.
Where these are consumer loans I originate them in select states; business-purpose versions are available more widely. Eligibility and terms vary by scenario and by lender guidelines; nothing here is a commitment to lend.