Not at all. The seller has their own priorities and price is only one them. Speed of Closing may be very important for example, in which case an all cash offer in a lower amount may be more attractive to the seller. You can't force a seller to sell to you unless you are already in a legally binding contract with him, although you are certainly likely to have a full price offer accepted if all the other elements of the offer, including the contingencies, are reasonable. The only situation in which you could argue that the seller should sell to you would be a full price all cash offer, 30 day close, "As-is", no contingencies,. This basically means that you walk through then write the check, with no home inspection, no appraisal, no warranty on any of the heating and plumbing, fixtures and fittings, no Cos, and no guarantees that roof doesn't leak and so on. The only thing the seller would have to provide would be "Clear Title". Home buyers would not normally want to do that, even if they could.
But a full price offer from a qualified buyer is a wonderful thing...good luck!