Crawl budget: do not waste Google's time
Google does not explore a site endlessly: it gives each one a limited time and page count. How you spend it matters.
If that time is wasted on duplicate pages, endless filters, useless versions and dead ends, the pages you really care about risk being found late or never. On small sites the problem is rare, but on large or poorly structured catalogs it becomes decisive.
How not to waste it
Keep the structure clean, avoiding thousands of near-identical URLs. Clearly signal what should not be explored. Fix dead ends and redirect chains. Offer an orderly sitemap that points to the pages that count. In short, make it easy for Google to find the good stuff.
It is work invisible to visitors, but it decides whether your best pages get seen by engines.
How we do it: we keep the site's technical structure tidy, so Google spends its time on the pages that earn you money.