Indeed, ClickHouse results were run on an older instance type of the same family and size (c5.4xlarge for ClickHouse and c6a.4xlarge for Timescale), so if anything ClickHouse results are at a slight disadvantage.
Eh, c6a is also an AMD Rome which has worse memory bandwidth at the tails and weaker per thread performance than Cascadelake (c5). I don't understand anything about this particular benchmark, but I wouldn't compare them simply as "older vs newer".
This is an open source benchmark - we'd love contributions from Timescale enthusiasts if we missed something: https://github.com/ClickHouse/ClickBench/