Food is an excellent reinforcer because it is convenient, measurable, and often highly motivating. But it isn't the only thing dogs value.
The environment can pay your dog
If your dog wants to sniff a bush, walking calmly toward that bush can be the reward. If they want to chase a toy, a successful response can earn a short game.
This is sometimes called using life rewards: allowing access to something the dog already wants as a consequence of useful behavior.
Match the reward to the situation
A small treat may work beautifully indoors but be less important than getting closer to an interesting smell outside.
Understanding what your dog actually wants in the moment can make training more efficient.
Don't remove food just to prove a point
There is no prize for never using treats. Food remains extremely useful, especially when teaching new behavior or working around major distractions.
The goal is flexibility. Your dog's reward system can include food, play, access, movement, sniffing, attention, and opportunities to explore.
Good training uses whatever consequence makes the desired behavior worthwhile in that particular situation.