Burns reduce total-supply. Some are mechanical, like the base-fee destroyed on every transaction; others are discretionary buyback-and-burn programmes funded from protocol revenue.
Mechanical burns tied to real usage are economically meaningful, resembling a share buyback funded by revenue. Announced burns of tokens the team never circulated are largely cosmetic: destroying unissued supply changes no float.
Example: burning 1% of a 1bn supply removes 10m tokens. If the float is 200m, that is a 5% reduction in tradable supply, a real effect. If those 10m sat locked in a treasury for five more years, the near-term effect is close to zero.
Related: total-supply, base-fee, tokenomics, minting