geizhals.at is regrettably only available in Austria, Germany, and the EU, but other sites I've used with similar good parametric search and filter are digikey.com (electronics engineering), https://at.rs-online.com (more electronics engineering), and McMaster.com (industrial manufacturing).
I've observed that developing and maintaining a database with the relevant attributes for each component is a ton of work and becomes a huge value-add for a distributor with technically inclined customers. It cannot be outsourced to manufacturers, as they have no incentive to match their schema to other manufacturers, and it cannot be outsourced to marketplace sellers, as they too lack this incentive. Both groups want their products to appear in as many searches as possible. Only the distributor wants exclusively the correct products to show up for a limited search and is in a position to enforce consistency across different marketplace listings and manufacturers.
On a side note, McMaster.com is the very best online shopping site I've ever visited or used. It's blazing fast (a trick based on pre-fetching that you can observe in all its glory in the developer view of your favourite browser), it's logical, uncluttered - perfect.
This efficiency extends to their customer support ops as well. I ordered the wrong size of a bin, sent a message in their chat saying I wanted to return the bins and get the ### SKU instead, and without any further input from me, there were new bins delivered 2 days later.
They seem to have the assumption that their customers are actually trying to get some shit done.
This 100%. McMaster quietly perfected e-commerce at some point, and because we’re live in a fallen world, nobody decided to follow their lead. If only we could convince McMaster to sell toilet paper and cereal…
Having marketplace sellers do it could probably work if the moderation had teeth. But (for example) I've reported intentionally miscategorized listings on ebay only to have an automated system reject the report.
On a related note, https://segor.de/ doesn't have great search (and they don't remotely attempt to carry every component, and note that a whole lot of German component names look nothing like their English counterparts) but the technical design of their online catalog is interesting - it's a fast single-page app with about 3MB of data, so when you navigate the catalog it doesn't do any network round-trips except to fetch images.
I've observed that developing and maintaining a database with the relevant attributes for each component is a ton of work and becomes a huge value-add for a distributor with technically inclined customers. It cannot be outsourced to manufacturers, as they have no incentive to match their schema to other manufacturers, and it cannot be outsourced to marketplace sellers, as they too lack this incentive. Both groups want their products to appear in as many searches as possible. Only the distributor wants exclusively the correct products to show up for a limited search and is in a position to enforce consistency across different marketplace listings and manufacturers.