The economic improvement "under" Lula was mostly due to international factors (the boon in the price of commodities) which is why it collapsed under Dilma (Lula's protegé).
Instead of using the economic surplus that fell into his lap to invest in infrastructure and industrialization, Lula used it to fund the largest corruption scheme in our history.
Edit: trickle down economics has no basis in reality either.
Just compare him to Temer, Bolsonaro and the entire Bolsonaro clan, which bought off Moro, is weakening protections for the rainforest (benefiting his associates), and is systematically dismantling anti-corruption institutions.
https://g1.globo.com/politica/noticia/2020/10/13/transparenc...
Just because the investigations haven't begun doesn't mean they're not coming.
It's a weak argument given the responsible alternatives to explore that benefit more people. The government deserves criticism.
Lula and Dilma spearheaded the biggest infrastructure investment in Brazilian history, both in absolute and relative terms. There was corruption, but the claim that it was the largest corruption scheme is laughable, a talking point of dumbass bolsonaristas.