A pre-approval is not a guarantee of financing. A lender still verifies income, debt and the specific property before final approval, but it narrows your search to homes you can actually afford and removes the guesswork from an offer.
In a market this tight, a seller comparing two similar offers will often favour the one backed by a pre-approval letter over one with a vague financing plan, since it lowers the risk the deal falls through partway.
Shopping without one risks falling for a home just outside your real range, then losing time reworking the search once a lender sets the actual number.
Get your hand-reviewed valuation from Joel Dyck.