It seems a paradox that the states voted away their power in the Senate so I looked into that. What happened was people were so excited over whoever the State legislator picked as Senator they became deeply engaged in the state elections. The 17th became the way state level politicians could occupy their office with little push-back.
Even if you did convene a convention, you could not reign in SCOTUS without repealing the 17th Amendment and requiring that each state government (rather than the people of the state as under 17A) select that states senators.And if you really wanted to rein in SCOTUS by constitutional amendment, you would name the actual names of the justices of SCOTUS. Which would dramatize the ability to actually override the lifetime appointment nature of the SCOTUS justice job.
The right way to modify SCOTUS would be to require that the most senior SCOTUS justices retire (subject to temporary reinstatement to fill vacancies) as necessary to hold the number of justices down to 11, even tho each newly inaugurated POTUS would name two new justices (which would map to a 22-year term for each new justice).
But I doubt that any such amendments can be ratified, unfortunately . . .