Locally grown tech ventures might also struggle to attract enough talent without changes to the education sector or if tech companies insist all workers return to an office.
Technology leaders issued the warnings at the National Tech Summit in Brisbane on Thursday including speakers from Atlassian, Google, Amazon and Microsoft.
Tech Council chair Robyn Denholm said its Shots on Goal study of startup funding found Australia had produced 100 tech firms worth more than $100 million, including 28 "unicorns" or businesses valued at more than $1 billion.
Ms Denholm, an Australian who chairs electric car giant Tesla, said the achievement represented a massive turnaround from the early 1990s.
"For a long time, particularly during the dotcom era, Australia was forced to watch billions of dollars in investment pouring into Silicon Valley with relatively little invested in our local startups at that time," she said.
"Today, Australia boasts a technology sector that employs over 935,000 Australians. That makes it equivalent to the (country's) seventh largest employer."
The analysis showed early-stage Australian startups could attract similar investments to US firms by 2030, but also revealed funding levels dropped significantly in later stages when companies were seeking to grow.
"Australian based startups appear to face significant challenges in scaling compared to startups in competitor countries," she said.
"We are currently on track to have a $53 billion funding gap for Australian startups by 2030."
Tech Council chief executive Kate Pounder said the growing investment in early startups was promising but the failure to support ventures in later stages could hold back the industry.
"Maybe that's a structural feature of our economy that we're finding it harder to sustain those companies when they get to that really critical level," she said.
The report also found Australia would fall short of the council's goal to see 1.2 million Australians employed in technology roles by 2030.
The nation would need more than 600,000 extra workers including 161,000 graduates, 295,000 upskilled workers and 150,000 migrants.
Changes would be needed to education and retraining opportunities as well as migration rules, Ms Denholm said.
Atlassian co-founder Scott Farquhar said tech companies should embrace flexible working arrangements to attract highly skilled workers regardless of where they live.
The multibillion-dollar firm employs 170 people in Queensland, he said, even though the company does not have an office there.
"Allowing people the flexibility to work means you can attract a whole new set of employees," Mr Farquhar said.
"Half of our employees we hired in the last two years couldn't have come to work for us if we didn't have that flexible and remote working environment."
