The new HS2 Euston station is intended to be the London terminus of the high-speed rail line, but it has been beset by issues. It was initially intended
It's not stated explicitly in the article, but my take is that the 7 platform Euston design is basically predicated on the assumption that Old Oak Common will be the "main" London terminus, with only a minority of services extended to Euston.
Which...well, I guess it's not complete insanity, but it is ridiculously short-sited.