Affecting nearly one in four workers - particularly younger people, women in low-paid industries, and newly arrived workers - the Super Members Council says it remains a systemic issue.
The analysis of tax office data underscored a need for tougher compliance and legislative reform, council chief executive Misha Schubert said, including payday super.
The federal government has committed to paying super at the same time as wages and salaries - rather than every quarter, as rules dictate at the moment - from mid-2026.
When paid at the same time as wages, employees are thought to have a better chance of noticing and resolving any incorrectly paid or missing super.
Ms Schubert warned the clock was ticking to get the changes over the line in this term of parliament, with consultation wrapped up but legislation yet to be introduced.
"Paying super on payday will modernise the super system and should hugely reduce underpayments," she said.
A spokesperson for Assistant Treasurer Stephen Jones said payday super was part of a broader agenda to bolster the system.
"The government has a significant policy agenda to strengthen the superannuation system so that all Australians can retire with dignity," the spokesperson said.
Opposition financial services spokesman Luke Howarth warned small businesses would face liquidity and cash flow challenges from more frequent super guarantee payments.
"Small businesses deserve certainty about if this will happen, when it will start and how it will work," he told AAP.
"Payday super can be added to the long list of legislation promised by the assistant treasurer that has been hugely delayed or is yet to materialise."
Super Members Council analysis released on Wednesday found about 2.8 million workers missed out on some of their entitlements in 2021/22, the same as in the previous 12 months and amounting to $5.1 billion in total.
The average affected worker missed out on $1800 in super in a year, leading to about $30,000 less at retirement for a typical worker.
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