Taken from the 5500-ez instruction:
"You do not have to file Form 5500-EZ for the 2023 plan year for a one-participant plan if the total of the plan’s assets and the assets of all other one-participant plans maintained by the employer at the end of the 2023 plan year does not exceed $250,000, unless 2023 is the final plan year of the plan. For more information on final plan years, see Final Return, later."
Why would you not start a traditional IRA or Roth IRA? If you aren't exceeding the limits for IRA's?